Advance acoustic Convertamatic 24D User manual

2/05 revised 8/06 FORM NO. 56043098
Convertamatic™24D, 26D, 28D
Convertamatic™24C, 26C, 28C
Service Manual
Advance Models 56315000(24D-C), 56315001(26D), 56315002(28D),
56315003(24C-C), 56315004(28D-C), 56315005(28C-C),
56315006(X24D-C), 56315007(X24C-C), 56315008(26D-C),
56315009(X26D-C), 56315010(26C-C), 56315011(X26C-C),
56315012(X28D-C), 56315013(X28C-C)

FORM NO. 56043098 - Convertamatic™24C, 24D, 26C, 26D, 28C, 28D - 1
TABLE OF CONTENTS
INTRODUCTION .......................................................................................................................................................................................... 2
CAUTIONS AND WARNINGS ...................................................................................................................................................................... 3
SPECIFICATIONS & MAINTENANCE ...................................................................................................................................................... 4-6
PM CHECKLIST ........................................................................................................................................................................................... 7
KNOW YOUR MACHINE......................................................................................................................................................................... 8-12
SOLUTION SYSTEM............................................................................................................................................................................. 13-19
FUNCTIONAL OVERVIEW....................................................................................................................................................................... 13
CIRCUIT OVERVIEW SOLUTION AUTO MODE ..................................................................................................................................... 14
SOLUTION SYSTEM MAINTENANCE .................................................................................................................................................... 15
TROUBLESHOOTING GUIDE ............................................................................................................................................................ 16-17
SOLUTION SOLENOID VALVE REMOVAL.............................................................................................................................................. 18
SOLUTION VALVE DISASSEMBLY AND CLEANING ............................................................................................................................. 18
SOLUTION FILTER AND BALL VALVE REMOVAL.................................................................................................................................. 19
SOLUTION PUMP REMOVAL.................................................................................................................................................................. 19
SCRUB SYSTEM .................................................................................................................................................................................. 20-25
GENERAL BRUSH SYSTEM FUNCTIONAL OVERVIEW ....................................................................................................................... 20
SPECIAL SCRUB SYSTEM FUNCTIONS .......................................................................................................................................... 20-21
SCRUB BRUSH DECK REMOVAL (DISC) .............................................................................................................................................. 22
SCRUB BRUSH LIFT ACTUATOR REMOVAL (DISC)............................................................................................................................. 22
SCRUB BRUSH MOTOR/GEARBOX REMOVAL (DISC) ........................................................................................................................ 23
SCRUB BRUSH DECK REMOVAL (CYLINDRICAL) .......................................................................................................................... 24-25
SCRUB BRUSH MOTOR(S) REMOVAL (CYLINDRICAL) .................................................................................................................. 24-25
SCRUB BRUSH BELT REPLACEMENT (CYLINDRICAL).................................................................................................................. 24-25
SCRUB BRUSH SYSTEM MAINTENANCE (CYLINDRICAL) ................................................................................................................. 24
SCRUB BRUSH REMOVAL AND INSTALLATION (CYLINDRICAL)........................................................................................................ 24
SCRUB BRUSH LIFT ACTUATOR REMOVAL (CYLINDRICAL).........................................................................................................24-25
RECOVERY SYSTEM........................................................................................................................................................................... 26-32
FUNCTIONAL OVERVIEW....................................................................................................................................................................... 26
VACUUM MOTOR CONTROL CIRCUIT OVERVIEW (AUTO MODE)..................................................................................................... 27
VACUUM/RECOVERY SYSTEM MAINTENANCE CHECKLIST ............................................................................................................. 28
MAINTENANCE OF RECOVERY TANK FLOAT SWITCHES .................................................................................................................. 29
MAINTENANCE OF VACUUM MOTOR INLET SCREEN........................................................................................................................ 30
VACUUM MOTOR REMOVAL.................................................................................................................................................................. 31
RECOVERY TANK REMOVAL ................................................................................................................................................................. 32
SQUEEGEE SYSTEM........................................................................................................................................................................... 33-36
SQUEEGEE LIFT LINKAGE ADJUSTMENT............................................................................................................................................ 33
SERVICING THE SQUEEGEE................................................................................................................................................................. 34
ADJUSTING THE SQUEEGEE ................................................................................................................................................................ 34
SQUEEGEE MOUNT ASSEMBLY REMOVAL ......................................................................................................................................... 35
CASTER WHEEL REMOVAL ................................................................................................................................................................... 36
WHEEL DRIVE SYSTEM ...................................................................................................................................................................... 37-45
GENERAL FUNCTIONAL OVERVIEW................................................................................................................................................ 37-39
WHEEL DRIVE TROUBLESHOOTING GUIDE........................................................................................................................................ 40
DRIVE MOTOR TRANSAXLE REMOVAL........................................................................................................................................... 41-42
DRIVE WHEEL REMOVAL....................................................................................................................................................................... 43
(5K) POTENTIOMETER (R1) TESTING AND REMOVAL........................................................................................................................ 44
(5K) POTENTIOMETER (R1) INSTALLATION AND ADJUSTMENT................................................................................................... 44-45
(100K) POTENTIOMETER (R2) TESTING AND REMOVAL.................................................................................................................... 45
ELECTRICAL SYSTEM......................................................................................................................................................................... 46-73
BATTERIES .............................................................................................................................................................................................. 46
DESCRIPTION OF THE LOW VOLTAGE CUTOUT FEATURE ............................................................................................................... 47
DESCRIPTION OF THE BATTERY CONDITION INDICATORS.............................................................................................................. 47
BATTERY CHARGING, MAINTENANCE AND TESTING ................................................................................................................... 48-49
ACTUATOR DRIVE NUT ADJUSTMENT ............................................................................................................................................ 50-51
CURTIS CONTROLLER...................................................................................................................................................................... 52-55
FUNCTIONAL OVERVIEW OF MAIN CONTROL BOARD ...................................................................................................................... 56
MAIN CONTROLLER ERROR CODES ................................................................................................................................................... 57
MAIN CONTROLLER DIAGNOSTIC SERVICE TEST MODE ............................................................................................................ 58-62
MAIN CONTROL PROGRAMING OPTIONS ...................................................................................................................................... 63-68
ELECTRICAL COMPONENT LOCATION ................................................................................................................................................ 69
WIRING DIAGRAM................................................................................................................................................................................... 70
WIRING SCHEMATIC .............................................................................................................................................................................. 71
APPENDIX............................................................................................................................................................................................. 72-74
DETERGENT (AXP) SYSTEM PLUMBING SCHEMATIC........................................................................................................................ 72
EXTENDED SCRUB SYSTEM PLUMBING SCHEMATIC ....................................................................................................................... 73
DETERGENT (AXP) SYSTEM PREPARATION AND USE ...................................................................................................................... 74
Note: All references to right, left, front, or rear in this manual are as seen from the operator’s stand-point.
revised 8/05

2- FORM NO. 56043098 - Convertamatic™ 24C, 24D, 26C, 26D, 28C, 28D
INTRODUCTION
This manual will help you get the most from your Convertamatic. Read it thoroughly before servicing the machine.
Note: Bold numbers and letters in parentheses indicate an item illustrated on pages 8-10.
PARTS AND SERVICE
Repairs, when required, should be performed by your Authorized Nilfisk-Advance Service Center, who employs factory trained service personnel, and maintains an
inventory of Nilfisk-Advance original replacement parts and accessories.
Call the NILFISK-ADVANCE DEALER named below for repair parts or service. Please specify the Model and Serial Number when discussing your machine.
(Dealer, affix service sticker here.)
NAME PLATE
The Model Number and Serial Number of your machine are shown on the Nameplate on the machine. This information is needed when ordering repair parts for the
machine. Use the space below to note the Model Number and Serial Number of your machine for future reference.
MODEL NUMBER ______________________________________________
SERIAL NUMBER ______________________________________________
TRANSPORTING THE MACHINE
CAUTION!
Before transporting the machine on an open truck or trailer, make sure that . . .
• The machine is tied down securely.
• All access doors and covers are secured (tape and strap as needed).
TOWING
CAUTION!
If the machine must be towed or pushed, make sure the Master On/Off Key Switch (A) is in the OFF position and do not move the
machine faster than a normal walking pace (2-3 mph, 3-5kph) and for short distances only. Note: Disconnecting the wheel drive motor
wiring connector will make a disabled machine easier to push.
OTHER MANUALS AVAILABLE FOR YOUR MACHINE
The manuals listed below can be found via Nilfisk-Advance’s two electronic supported databases. They are:
• Nilfisk-Advance Dealer Customer Zone
• Ezparts service / parts CD-Rom
• 56041596 – Instructions for Use
• 56042451 – Parts List

FORM NO. 56043098 - Convertamatic™24C, 24D, 26C, 26D, 28C, 28D - 3
CAUTIONS AND WARNINGS
SYMBOLS
Nilfisk-Advance uses the symbols below to signal potentially dangerous conditions. Read this information carefully and take the
necessary steps to protect personnel and property.
DANGER!
Is used to warn of immediate hazards that will cause severe personal injury or death.
WARNING!
Is used to call attention to a situation that could cause severe personal injury.
CAUTION!
Is used to call attention to a situation that could cause minor personal injury or damage to the machine or other property.
Read all instructions before using.
GENERAL SAFETY INSTRUCTIONS
Specific Cautions and Warnings are included to warn you of potential danger of machine damage or bodily harm.
WARNING!
*This machine should only be used by properly trained and authorized persons.
* While on ramps or inclines, avoid sudden stops when loaded. Avoid abrupt sharp turns. Use low speed down hills. Clean only while ascending (driving up)
the ramp.
*Keep sparks, flame and smoking materials away from batteries. Explosive gases are vented during normal operation.
*Charging the batteries produces highly explosive hydrogen gas. Charge batteries only in well-ventilated areas away from open flame. Do not smoke while
charging the batteries.
*Remove all jewelry when working near electrical components.
*Turn the key switch off (O) and disconnect the batteries before servicing electrical components.
*Never work under a machine without safety blocks or stands to support the machine.
*Do not dispense flammable cleaning agents, operate the machine on or near these agents, or operate in areas where flammable liquids exist.
*Do not clean this machine with a pressure washer.
*Do not operate this machine on ramps or inclines of more than a 2 percent gradient.
*Only use the brushes provided with the appliance or those specified in the instruction manual. The use of other brushes may impair safety.
CAUTION!
*This machine is not approved for use on public paths or roads.
*This machine is not suitable for picking up hazardous dust.
*Use care when using scarifier discs and grinding stones. Nilfisk-Advance will not be held responsible for any damage to floor surfaces caused by scarifiers or
grinding stones.
*When operating this machine, ensure that third parties, particularly children, are not endangered.
*Before performing any service function, carefully read all instructions pertaining to that function.
*Do not leave the machine unattended without first turning the key switch off (O), removing the key and securing the machine.
* Turn the key switch off (O) and remove the key, before changing the brushes, and before opening any access panels.
*Take precautions to prevent hair, jewelry, or loose clothing from becoming caught in moving parts.
* Use caution when moving this machine in below freezing temperature conditions. Any water in the solution or recovery tanks or in the hose lines could freeze,
causing damage to valves and fittings. Flush with windshield washer fluid.
* The batteries must be removed from the machine before the machine is scrapped. The disposal of the batteries should be safely done in accordance with your
local environmental regulations.
*Do not use on surfaces having a gradient exceeding that marked on the machine.
*All doors and covers are to be positioned as indicated in the instruction manual before using the machine.
* Refer to “Onboard Battery Charger” section at back of manual for additional specific battery charger warnings.
SAVE THESE INSTRUCTIONS

4- FORM NO. 56043098 - Convertamatic™ 24C, 24D, 26C, 26D, 28C, 28D
TECHNICAL SPECIFICATIONS
Voltage 24 Volt
Power Source (4) 6 volt batteries (wet acid and gel cell available)
Onboard Battery Charger 24 volt, 25 amp Wet/Gel Compatible
Solution Control Precision-Flow electric pump
Solution Tank 20 gal. (76L)
Recovery Tank20 gal. (76L)
Scrub Motors (2) .50 hp (375 watt)
Vacuum Motor 0.75 hp (560 watt) 3-stage
Sound Level 66 dB(A) at operator’s position
Drive System 0.4 hp (300 watt) variable forward and reverse, max speed =3 mph (4.83 km/hr), 10% gradeability
Drive Wheels (2) 7 in. (18cm) dia. foam-filled, gray non-marking
Convertamatic 24D Convertamatic
26D
Convertamatic
28D
Convertamatic
24C
Convertamatic
26C
Convertamatic
28C
Scrub Head Type Disc Cylindrical
Scrub Path 24 in (61cm) 26 in (66cm) 28 in (71cm) 24 in (61cm) 26 in (66cm) 28 in (71cm)
Max Productivity @ 2.8 mph 29,600 ft²/hr 32,050 ft²/hr 35,000 ft²/hr 29,600 ft²/hr 32,050 ft²/hr 35,000 ft²/hr
(2,750m²/hr) (3,000 m²/hr) (3,200 m²/hr) (2,750m²/hr) (3,000 m²/hr) (3,200 m²/hr)
Max Productivity @ 1.5mph 15,800 ft²/hr 17,200 ft²/hr 18,500 ft²/hr 15,800 ft²/hr 17,200 ft²/hr 18,500 ft²/hr
(1468 m²/hr) (1598 m²/hr) (1719 m²/hr) (1598 m²/hr) (1598 m²/hr) (1719 m²/hr)
Scrub Head Size & Type (2) 12 in (30.5 cm) brushes or pad holders
(2) 13 in (33 cm)
brushes or pad
holders
(2) 14 in (35.5 cm)
brushes or pad
holders
(2) 23 in (58 cm)
brushes
(2) 25 in (64 cm)
brushes
(2) 27 in (69 cm)
brushes
Scrub
Pressure
Regular Scrub max 80 lbs max 60 lbs
Heavy Scrub max 130 lbs max 80 lbs
Extreme Scrub max 160 lbs max 100 lbs
Scrub Head Speed 220 rpm 900 rpm
Solution
Flow Rate
Regular Scrub .25 gal/min (.95 L/min) or 80 minutes per solution tank
Heavy Scrub .50 gal/min (1.9 L/min) or 40 minutes per solution tank
Extreme Scrub .75 gal/min (2.8 L/min) or 27 minutes per solution tank
Squeegee Width 32.6 in (83 cm) 36.6 in (93 cm) 36.6 in (93 cm) 32.6 in (83 cm) 36.6 in (93 cm) 36.6 in (93 cm)
Dimensions (w/o squeegee) W=26 in (66 cm) L=54.5 in (138 cm) H=44 in (112 cm)
W=27.5 in (70 cm)
L=55 in (140 cm)
H=44 in (112 cm)
W=30 in (76 cm)
L=55.5 in (141 cm)
H=44 in (112 cm)
W=27 in (69 cm)
L=55 in (140 cm)
H=44 in (112 cm)
W=29 in (74 cm)
L=55 in (140 cm)
H=44 in (112 cm)
W=31 in (79 cm)
L=55 in (140 cm)
H=44 in (112 cm)
Weight w/ Batteries 780 lb (354 kg) 780 lb (354 kg) 780 lb (354 kg) 780 lb (354 kg) 780 lb (354 kg) 780 lb (354 kg)
Smart Solutions AXP
Refillable Cartridge Capacity 1.25 gal (4.75 L)
Available Dilution Rates 32:1, 50:1, 64:1, 100:1, 128:1, 150:1, 200:1, 256:1, & 300:1
Low Detergent Warning Standard

FORM NO. 56043098 - Convertamatic™24C, 24D, 26C, 26D, 28C, 28D - 5
SPECIFICATIONS

6- FORM NO. 56043098 - Convertamatic™ 24C, 24D, 26C, 26D, 28C, 28D
MAINTENANCE SCHEDULE
Maintenance intervals given are for average operating conditions. Machines used in severe operational environments may require service more often.
MAINTENANCE ITEM Daily Weekly Monthly Yearly
Charge Batteries X
Check/Clean Tanks & Hoses (clean recovery tank switches & vacuum inlet screen) X
Check/Clean/Rotate the Brushes/Pads X
Check/Clean the Squeegee X
Clean Hopper on Cylindrical System X
Purge Extended Scrub System (if installed) X
Check Each Battery Cell(s) Water Level (does not apply to gel cell batteries) X
Inspect Scrub Housing Skirts X
Inspect and clean Solution Filter X
Clean Solution Trough on Cylindrical System X
Lubricate the Machine X
* Check Carbon Brushes X
Note: See the individual machine system sections for maintenance information.
* Have Nilfisk-Advance check the vacuum motor carbon motor brushes once a year or after 300 operating hours. The brush and drive motor carbon brushes check
every 500 hours or once a year.
WARNING!
Turn the key switch off and disconnect the batteries before servicing the machine.
* Check vacuum motor carbon brushes (Qty 2) once a year or after 300 operating hours.
* Check brush and wheel drive motor(s) carbon brushes (Qty 4 per motor) once a year or after 500 operating hours.
* The original (new) length of each carbon brush is 1” (25.4mm) on all 24 volt machine models brush and wheel drive motors.
* All motors: Replace carbon brushes when shorter than 3/8” (9.5mm) to obtain the same motor efficiency as new brushes.
IMPORTANT!
Motor damage resulting from failure to service the carbon brushes is not covered under warranty. See the Limited Warranty
Statement.
BATTERIES AND CHARGERS
Attention: See the ELECTRICAL SYSTEM section for battery installation, battery maintenance and charger system requirements.
LUBRICATING THE MACHINE
Once a month, apply light machine oil to lubricate the:
• General Pivot Points for the Squeegee Linkage (A).
• Squeegee mount angle adjustment knob threads (B).
• Squeegee Tool end wheels (C).
• General Pivot Points for the Brush Linkage (D).
• Scrub Deck Bumper Wheels.
Once per quarter, Grease the following
• Rear Caster Wheel Swivel (E).
revised 8/05

Advance Convertamatic™24/26/28 C/D Models
Cylindrical and Disc
PM Checklist
Defect Codes
Customer A needs adjustment
Bbinding
Address C dirty or contaminated
Ddamaged, bent or torn
City St Zip L leaks
Mmissing
Model Serial Hours W worn out
Ref
OPERATIONAL INSPECTION ITEMS
OK
Defect Codes
(circle)
Does
Not
Work
1 Drive Paddle Operation (check for Fwd/Rev Drive & any neutral creep) A B D
2 Drive System Performance (Speed Changes Min/Max) noisy sluggish
3 Scrub System (Raise/Lower, Brush Motor On/Off & Optional Brush Remove Feature) A B D
4 Scrub Brush Pressure settings (1-3) A B
5 Squeegee System (Raise/Lower & Squeegee Tool pickup Performance) A B D
6 Vac Performance (Sealed water lift & 1” open hole adapter, 24v-56/9) C L W
7 Solution Control (On/Off Manual /Auto and Flow Volume settings 1,2 &3) A B L
8 Battery Charger (Auto turn ON & OFF) D
9 Main Controller Special Program Options (see SVR manual 56043098). Check all applicable
machine settings. Examples: Scrub mode pressure settings, SVR test mode, low voltage cutout
etc.
A
Ref
VISUAL INSPECTION ITEMS
Comments OK
Defect Codes
(circle)
Does
Not
Work
10 Scrub Brushes, check for wear and rotate D M W
11 Scrub Brush Motor(s), check for carbon brush wear 500 Hours B C W
12 Scrub Brush Motor(s), check gearboxes (disc) B D L
13 Brush Drive Plate Retainer Clips & flex couplers (disc) C D M
14 Scrub Deck Lift Motor, Skirt & Side Wheel D M W
15 Solution Solenoid Valve C L W
16 Solution Pump & Hoses C L W
17 Solution Tank, Delivery Hoses & Filter clean filter screen C L
18 Vacuum Motor Carbon Brushes (wear limit 3/8”) 300 Hours B C W
19 Vacuum motor inlet filter (located in recovery tank) clean screen C D M
20 Recovery Tank Cover Gasket L M W
21 Recovery Tank Drain Hose & Cap C D L
22 Squeegee Pick-Up Hose back flush C D L
23 Squeegee Tool & Blades (clean, rotate & adjust) A D W
24 Squeegee Tool lift cable & mount Wheels (lubricate) two side & one floor A D W
25 Battery Condition (load test, clean & water) C W
26 Drive Wheel Trans Axle Motor Check Carbon Brushes 500 Hours B C D W
27 Trans Axle Drive Tires tread wear W
28 Rear chassis Caster Wheel (Lubricate) tread wear W
NOTE: For additional service information see service manual form number 56043098 and operator manual form
number 56041596.
WORK COMPLETED BY: ACKNOWLEDGED BY:
Service Technician Signature Date Customer Signature Date

8- FORM NO. 56043098 - Convertamatic™ 24C, 24D, 26C, 26D, 28C, 28D
KNOW YOUR MACHINE
As you read this manual, you will occasionally run across a bold number or letter in parentheses - example: (2). These numbers refer to an item shown on this page
unless otherwise noted. Refer back to this page whenever necessary, to pinpoint the location of an item mentioned in the text. NOTE: Refer to the service manual
for detailed explanations of each item illustrated on the next 3 pages.
1 Solution Tank Fill
2 Operator Control Handle
3 Bottle Holders
4 Vacuum Motor Inlet Screen
5 Recovery Tank Cover
6 Detergent (AXP) Cartridge Access Cover
6a Detergent (AXP) Cartridge (AXP models only)
7 Scrub Deck
8 Scrub Deck Skirt
9 Scrub Deck Bumper
10 Drive Wheel
11 Solution Filter
12 Squeegee Assembly
13 Solution Shut-Off Valve

FORM NO. 56043098 - Convertamatic™24C, 24D, 26C, 26D, 28C, 28D - 9
KNOW YOUR MACHINE
14 Solution Drain Hose / Level Indicator
15 Squeegee Raise / Lower Lever
16 Onboard Battery Charger (Not found on all models)
17 Wheel Drive Circuit Breaker
18 Control Circuit Circuit Breaker
19 Squeegee Blade Latch
20 Squeegee Mount Thumb Nut
21 Squeegee Adjustment Knob
22 Recovery Tank Drain Hose
23 Debris Hopper (Cylindrical Models Only)
24 Idler Assembly (Cylindrical Models Only)
25 Battery Pack Connector (non onboard charger models only)
25a Battery Pack Connector (onboard charger models only)
26 Squeegee Blade Tension Strap
27 Squeegee Blade Alignment Pins
28 Recovery Hose
29 Control Panel
30 Drive Paddle
31 Speed Limit Control Knob
32 Vacuum Shut Off Switch
33 Extended Scrub Filter (Optional)
34 Solution Manifold (Cylindrical Models Only)

10 - FORM NO. 56043098 - Convertamatic™ 24C, 24D, 26C, 26D, 28C, 28D
KNOW YOUR MACHINE
A Key Switch (Main Power)
B Solution Switch
C Vacuum Switch
D Display Panel
Solution Flow Indicator
AXP Indicator
Hour Meter
Battery Indicator
Scrub Pressure Indicator
Recovery Tank FULL Indicator
Fault Indicator
E Wand Switch (Dealer Installed Option)
F Detergent System (AXP models only)
G Extended Scrub System (Dealer Installed Option)
H Scrub OFF
I Scrub ON

FORM NO. 56043098 - Convertamatic™24C, 24D, 26C, 26D, 28C, 28D - 11
KNOW YOUR MACHINE
FUNCTIONAL DESCRIPTION OF CONTROL PANEL:
The controls on the Convertamatic were designed with one touch operation in mind. For single pass scrubbing the user can simply depress one
switch and all systems on the machine will be ready to go. For most single-pass scrubbing operations, the operator should only need to use the
middle switches on the control panel. These are the Scrub System OFF and Scrub system ON switches.
Scrub OFF Switch (H) - Pressing this switch when the unit is in a scrub mode will cause the following to occur:
• The scrub brushes will turn off and the scrub deck will be raised to the up position
• The solution flow will be stopped
• The first time that this switch is pressed, the vacuum system will NOT be turned off. This is so that any remaining water may be picked up without
having to turn the vacuum back on. If this switch is pressed a second time (pressed after the scrub system has been turned off) the vacuum will shut
of after a 10 second delay.
Scrub ON Switch (I) – If the scrub system is off, pressing this switch once will cause the following to occur:
• The scrub system will be enabled with the scrub pressure set to the regular setting and the scrub deck will be lowered. Note press twice for the
heavy scrub pressure mode and hold this switch for 5 seconds to enter the extreme scrub mode.
• The vacuum system will be enabled.
• The solution system will be enabled.
• As soon as the throttle (operator drive paddle) is moved from the neutral position the scrub brushes will start turning and the vacuum will turn on. If
the direction is forward the solution flow will start. If the direction is reverse, the solution flow will be stopped. If the scrub system is already enabled
when this switch is pressed, the scrub pressure will increase to the heavy scrub mode. If the switch is held for 5 seconds the pressure will change
to the extreme scrub mode. At the same time the panel display will show the correct changed scrub pressure setting.
Wand Switch (E) – This switch is used when an external vacuum/scrub wand is used. Pressing this switch will turn the vacuum on continuously
without regard to the throttle position. If the scrub system was on it will be turned off. This includes turning off the scrub brushes and turning the
solution flow off (to the scrub deck). NOTE: automatic shutoff of the vacuum motor when the recovery tank is full is disabled when the wand is
enabled.
Key Switch (A) – Main power switch
Vacuum Switch (C) – This switch is used to turn the vacuum system on or off. Pressing this switch will alternate between on and off. The vacuum
will only turn on when the throttle is moved from the neutral position. It will remain on for 10 seconds after the throttle returns to neutral.
The vacuum also has an automatic shutoff feature that will turn the vacuum and scrub systems off if the recovery tank becomes full.
Solution Switch (B) - This switch is used to turn the solution system on or off. Pressing this switch when the scrub system has been activated will
alternate between on and off. The solution flow will only turn on when the throttle is moved from the neutral position in the forward direction. The
solution flow will turn off if the throttle returns to neutral or is moved to reverse. Pressing this switch when the scrub system is off will momentarily
turn the solution flow on to allow pre-wetting of the scrub brushes.
Chemical Switch (F) – Pressing this switch will turn on or off the chemical option. See the main programming options in this manual to select
(activate) the onboard chemical distribution system.
Extended Scrub (Recycle) Switch (G) - Pressing this switch will turn on or off the recycle option. See the main programming options in this manual
to select (activate) the recycle option.

12 - FORM NO. 56043098 - Convertamatic™ 24C, 24D, 26C, 26D, 28C, 28D
KNOW YOUR MACHINE
DESCRIPTION OF INDICATORS ON THE CONTROL PANEL:
In general, the following guidelines apply to the control panel indicators:
A flashing green or yellow indicator means that a fault has occurred in the particular system. An example of this would be an over-current fault.
A yellow indicator means that the particular function has been enabled but is not currently on. For example, if a scrub mode is selected and the
throttle is in neutral, the scrub system, vacuum, and solution indicators will all be yellow indicating that the systems are enabled and ready to turn
on when the throttle is moved to forward or reverse.
A green indicator means that the particular system is on.
A flashing green indicator means that the particular system is in a delayed-off condition. An example of this is when a scrub mode is selected and
the throttle goes from forward or reverse to neutral. When this happens the vacuum indicator will flash green indicating that the vacuum is still on but
that it will be turning off after the delay period.
Scrub OFF Indicator (J):
• This indicator will be green if the scrub system is off and ready to be activated.
• This indicator will be red if the scrub system has been turned off and the scrub deck is not up yet.
• This indicator will flash red if there is a fault in the scrub system.
• This indicator will be off if the scrub system has been activated.
Regular Scrub ON Indicator (K):
• This indicator will be yellow if the scrub system is enabled in “Regular” scrub mode but the drive paddle is in neutral.
• This indicator will be green if the scrub system has been turned on in “Regular” scrub mode and the machine is moving in either direction.
• This indicator will be off if the scrub system has been turned OFF.
Heavy Scrub ON Indicator (L):
• This indicator will be yellow if the scrub system is enabled in “Heavy” scrub mode but the drive paddle is in neutral.
• This indicator will be green if the scrub system has been turned on in “Heavy” scrub mode and the machine is moving in either direction.
• This indicator will be off if the scrub system has been turned OFF.
Extreme Scrub ON Indicators (K & L):
• Both of these indicators will be yellow if the scrub system is enabled in “Extreme” scrub mode but the drive paddle is in neutral.
• Both of these indicators will be green if the scrub system has been turned on in “Extreme” scrub mode and the machine is moving in either
direction.
Control panel LED Display (D):
See the detailed drawing shown in the Know Your Machine manual section for the specific description of the individual icon symbols. NOTE: If a
speed control fault occurs (error code 3) the wand indicator will flash the fault code produced by the Curtis speed control. Refer to the service manual
troubleshooting section for details.
Wand Switch Indicator (M):
• This indicator will be green if the Wand Switch has been turned ON.
• This indicator will be off if the Wand Switch has been turned OFF.
Vacuum System Indicator (N):
• This indicator will be green if the vacuum is on.
• This indicator will flash green if the vacuum is in the 10 second delayed-off condition.
• This indicator will be yellow if the vacuum is enabled but the drive pedal is in neutral.
• This indicator will flash yellow if there is a vacuum system fault.
• This indicator will be off if the vacuum is disabled and turned off.
Solution System Indicator (O):
• This indicator will be green if the solution is on.
• This indicator will be yellow if the solution is enabled but the drive paddle is in neutral.
• This indicator will flash yellow if there is a solution system fault.
• This indicator will be off if the solution is disabled and turned off.
Chemical “AXP” System Indicator (P):
• This indicator will be green if the AXP system is on.
• This indicator will be yellow if the AXP system is enabled but the drive paddle is in neutral.
• This indicator will be off if the AXP system is disabled and turned off.
Extended Scrub System Indicator (Q):
• This indicator will be green if the Extended Scrub system is on.
• This indicator will be yellow if the Extended Scrub system is enabled but the recovery tank switches haven’t been activated.
• This indicator will be off if the Extended Scrub system is disabled and turned off.

FORM NO. 56043098 - Convertamatic™24C, 24D, 26C, 26D, 28C, 28D - 13
SOLUTION SYSTEM
FUNCTIONAL OVERVIEW
See Figure 1. The Convertamatic models have a solution tank fill capacity of 20-gallons (76 liters). All models use one right rear tank fill opening, which offers ease
of filling. Plumbed into the manual solution shut off valve outlet is a serviceable Solution Filter (C), to keep debris from entering the solenoid valve. Also fitted to the
tank is a flexible Clear Hose (B) used to indicate the solution level and to drain the tank for system maintenance.
The standard solution system uses an electrical Solenoid Valve (L1) which stops and starts the solution flow to the scrub brushes. The M7 water pump (A) located on
the machine chassis controls the needed flow volume demand to the scrub brushes. See Electrical Diagram Figure 2. The electrical circuit that turns on (energizes)
the solenoid coil and water pump is activated through the (A1) control panel’s solution switch button input and the FWD / REV (A2) Speed Controller voltage output
signals. Note: See the Know Your Machine section in this manual for a complete explanation of the solution operation modes.
During normal machine scrubbing the solution system’s Auto Mode is selected and works in conjunction with the wheel drive speed controller and the (A1) main
controller’s scrub system outputs to turn On & Off the (L1) solenoid valve and pump. The solution will flow to the scrub brushes when the scrub deck is lowered and
the handle drive paddle (box) is pushed Fwd. Note: When the solution On/Off button is turned Off, no flow can occur while the machine scrub deck is down and the
drive paddle activated.
*Note: Figure 1 shows the solution components of a machine with the Chemical System. The Chemical Tank Assembly is not found on all models.
FIGURE 1

14 - FORM NO. 56043098 - Convertamatic™ 24C, 24D, 26C, 26D, 28C, 28D
SOLUTION SYSTEM
CIRCUIT OVERVIEW SOLUTION AUTO MODE (SOLENOID VALVE CIRCUIT)
See Figure 2.
+ (Positive) circuit input starts with:
• A closed S3 key switch will direct the needed positive voltage (BRN wires) to the L1 solenoid coil and A1 control board terminal #J1-13.
- (Negative) circuit input starts with:
• A battery negative ground input at the A1 control board terminal #B2 (J1-9)
• The A1 control board solution button enabled.
• A negative voltage output from the A2 speed controller’s (pin #6) Red/Blk wire to the A1 control board Red/Blk wire (terminal J1-5). Note: The A2 speed controls
brake output (pin #6) occurs whenever the R1 direction throttle pot is moved off its neutral setting.
• A negative voltage output from the A1 board’s terminal J1-11 Red/Grn wire is direct to the L1 solenoid coil turning it on to allow flow through the valve body.
CIRCUIT OVERVIEW SOLUTION AUTO MODE (SOLUTION PUMP CIRCUIT)
See Figure 2.
+ (Positive) circuit input starts with:
• With the batteries connected the needed positive voltage (Red wires) to the M7 Solution Pump.
- (Negative) circuit input starts with:
• A battery negative ground input at the A1 control board terminal #B4 (J2-6)
• The A1 control board solution button enabled.
• A negative voltage output from the A2 speed controller’s (pin #6) Red/Blk wire to the A1 control board Red/Blk wire (terminal J1-5). Note: The A2 speed controls
brake output (pin #6) occurs whenever the R1 direction throttle pot is moved off its neutral setting.
• A negative voltage output from the A1 board’s terminal J1-8 Grn/Blk wire is direct to the M7 Solution Pump turning it on to allow flow to the L1 Water Valve
Solenoid. NOTE: The solution pump’s output volume is controlled by the A1 board’s programmable capability and changes the pulsing of the negative battery
connection to the pump.
Electrical Diagram
*For complete description of all callouts see Electrical System Wiring Diagram.
FIGURE 2
S1 M7
SOLUTIONPUMP
M
12 -+ GRN/BLK
RED
NOTE:SWITCHISPARTOF
PUMPASSEMBLY
R1
POT.5KOHMTHROTTLE
R2
POT.100KOHMSPEEDLIMIT
S3
SW,SPSTKEY
M1
MOTOR,WHEELDRIVE
M
F3
CIRCUITBREAKER,30AMP
F2
CIRCUITBREAKER,5AMP
L1
COIL,SOLUTIONSOLENOID
1
2
3
1
2
3
12
12
12
WHT
BRN/BLK
YEL/RED
RED
GRN
BRN
BLU
BLK
RED/BLK
BRN
RED/BLK
WHT/YEL
BRN
RED/GRN
RED
BLU/BLK
BLK
GRN/BLK
BLK
BLK
BLK
BLU/BLK
BRN
WHT
BLU
BLK
BRN
WHT
BLK
+
-
B+1
SOLUTION
FOR/REV.
J1-13
J1-11
REVERSE
B-1
SOL.PUMP
B-4
B-2
A1
CONTROLBOARD
J1-5 J1-6
J1-7
J1-8
J2-6
J1-9
A2 B+ B-
1210SPEEDCONTROLLER
M1
M2
PIN3-POT.HI
PIN4-POT.WIPER
PIN13-POT.LO
PIN5-KSI
PIN16-REV
PIN6-BRAKE(-)
(1228FOR36V)
PIN9-STATUS
PIN18-SPEEDLIMITPOT
F1
FUSE,150A.
BT1
BATTERY
12
+-
RED
RED
BLK
24VDCOR36VDC

FORM NO. 56043098 - Convertamatic™24C, 24D, 26C, 26D, 28C, 28D - 15
SOLUTION SYSTEM
SOLUTION SYSTEM MAINTENANCE
• Solution Tank: See Figure 1. Weekly empty the solution tank; remove the solution Drain Hose (B) from its storage area (located on the right rear control handle
compartment). Direct the hose to a designated “Disposal Site” and flush the tank with clean water.
• Solution Filter: Remove and clean the inline Solution Filter (C). To access the filter housing for removal, work underneath the middle left side chassis panel. No
tools are needed to remove the filter (hand tighten only). Service Tip: The solution filter ball valve must be placed in the OFF (Closed) position. This prevents loss
of solution when servicing the filter strainer with a partial or full tank.
• Solution Delivery Trough: On the cylindrical scrub deck clean the holes in the delivery trough to assure even distribution of solution.
TROUBLESHOOTING GUIDE
Problem Possible Cause
Inadequate or no solution flow No solution in the tank
Solution tank filter ball valve in the off position
Clogged solution filter, valves and hoses
*Reference the Solution System Troubleshooting Guide flowchart in this manual section for further component diagnostics.

16 - FORM NO. 56043098 - Convertamatic™ 24C, 24D, 26C, 26D, 28C, 28D
SOLUTION SYSTEM
TROUBLESHOOTING GUIDE ELECTRICAL
Possible Symptoms
1-No solution flow while in the scrub auto solution mode.
2-Solution Pump will not operate:
SYMPTOM ONE
Note: Activate the Service Test Mode Program. See optional program section for instructions.
All testing will be performed in the Service Test Mode Program.

FORM NO. 56043098 - Convertamatic™24C, 24D, 26C, 26D, 28C, 28D - 17
SOLUTION SYSTEM
TROUBLESHOOTING GUIDE ELECTRICAL (CONTINUED)
SYMPTOM TWO
Note: Activate the Service Test Mode Program. See optional program section for instructions.
All testing will be performed in the Service Test Mode Program.

18 - FORM NO. 56043098 - Convertamatic™ 24C, 24D, 26C, 26D, 28C, 28D
SOLUTION SYSTEM
SOLENOID VALVE REMOVAL
1 Drain the solution tank or turn the solution filter ball valve to the off position to prevent solution loss.
2 Lower the deck and disconnect the battery supply to the machine.
3 Remove the front Nose Cone from the machine by firmly grasping the lower part and lifting straight up.
4 See Figure 3. Unplug the L1 solenoid valve wire assembly connection from the machine harness.
5 Unscrew the inlet Hose Clamps (D) that secure the hoses to the valve body.
6 Separate (pry) the solution outlet hose off from its valve body barbed fitting.
7 Remove the (2) Hex Screws (E) that secure the valve to the Mount Bracket (F), then pull the valve body to the front separating it from the solution inlet Hose
(G), completing the part removal.
SOLENOID VALVE DISASSEMBLY AND CLEANING
1 Remove the solenoid valve. See the Solenoid Valve Removal section for instructions.
2 See Figure 3. Remove the (4) (H) Screws and disassemble the valve (be careful not to lose any internal parts).
3 Thoroughly wash dirt from block (I) and diaphragm (J).
4 After reassembling, test the solenoid valve for proper operation.
FIGURE 3