Jamar RAC Plus I User manual

i
RAC Plus I User’s Manual

RAC Plus I User’s Manual
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WARNING
Use of the RAC Plus I while driving could cause an accident, resulting in serious injury
or death. As with any in-vehicle instrumentation, the information provided by the RAC
Plus I should be observed as part of the normal operation of the vehicle. Changes to the
RAC Plus I should only be done in a safe manner.
Installation of the RAC Plus I and distance sensor should be done with caution so it
does not cause unsafe conditions.
DO NOT mount the RAC Plus I where it will obstruct the driver's view.
DO NOT mount the RAC Plus I over or near an air bag.
DO NOT route cables in a manner that would interfere with operation of the vehicle.
LIMITED WARRANTY
JAMAR Technologies, Inc. warrants the RAC Plus I for a period of five (5) years limited
warranty against defects in material and workmanship as follows: first year, parts and
labor; years two through five, parts only, flat labor charge. Sensors, cables, connectors,
brackets and other hardware are warranted for ninety (90) days.
JAMAR Technologies, Inc. warrants each new instrument manufactured by the company
to be free from defective material and workmanship and agrees to remedy any such defect.
At its option, it may furnish a new part in exchange for any part of any instrument of its
manufacture which, under normal installation, use and service discloses such defect. The
instrument must be returned to the JAMAR factory or authorized service agent intact,
for examination, with all transportation charges prepaid.
This warranty does not extend to any products which have been subject to misuse,
neglect, accident, incorrect wiring not our own, improper installation or use in disregard
of instructions furnished by JAMAR. This warranty does not extend to products which
have been repaired or altered outside the JAMAR factory or authorized service agent.
In no event shall JAMAR Technologies, Inc. be liable for any damages arising from the
use of this product including damages arising from the loss of information.
This warranty is in lieu of all other warranties expressed or implied and no representative
or person is authorized to assume for JAMAR Technologies, Inc. any other liability in
connection with the sale or use of JAMAR products.
JAMAR Technologies, Inc. reserves the right to make improvements on the product and/
or specifications at any time without notice. Questions concerning this warranty or any
JAMAR Technologies, Inc. product should be directed by e-mail, mail or telephone to:
JAMAR Technologies, Inc.
1500 Industry Road, Suite C, Hatfield, PA 19440
215-361-2244 • [email protected]
Copyright 2012 by JAMAR Technologies, Inc.

iii
Table of Contents
Volume 2.4 November 2012
If you have any questions about the use of the RAC Plus I, please call the
following number:
1-215-361-2244
Monday — Friday, 8:00 AM to 5:00 PM Eastern time
You may also contact us by e-mail at:
[email protected]
For more information on our products, or for the latest news in product
development, visit our web site at:
www.jamartech.com
For support information specific to the RAC Plus devices, go to:
www.jamartech.com/RACPlusSupport.htm
Address any correspondence to:
JAMAR Technologies, Inc.
1500 Industry Road, Suite C
Hatfield, PA 19440
We are pleased that you have chosen the RAC Plus I for your distance measuring
needs. We have strived to develop a unit that is easy to use and has the options that
our customers require. The RAC Plus I has undergone extensive testing to verify
the accuracy of its operations, and each unit is tested before it leaves our facility.
However, just like other complex electronic devices, problems can occur. We always
suggest that users verify the continuing accuracy of any device they use. Should you
detect any problems with any of our products, please notify JAMAR Technologies
immediately and discontinue use of the unit until we have verified its operation.

RAC Plus I User’s Manual
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Table of Contents
Technical Support ........................................................... iii
Quick Start Guide .............................................................v
Introduction to the RAC Plus I ......................................................... 1-1
What is the RAC Plus I? ......................................................... 1-2
How Does It Work? ......................................................... 1-3
Installation ......................................................... 2-1
Before You Begin ......................................................... 2-2
Installing the OBD Distance Sensor ....................................... 2-3
Installing the Modular Distance Sensor .................................. 2-6
Installing the Magnetic Distance Sensor .............................. 2-10
Installing the RAC Instrument .............................................. 2-15
Calibration ......................................................... 3-1
Automatic Calibration Procedure ........................................... 3-2
If Your RAC Fails to Calibrate ................................................ 3-5
Manual Calibration Procedure ................................................ 3-7
Key Functions & Operating Procedures .......................................... 4-1
RAC Plus I Key Functions ...................................................... 4-2
RAC Plus I Menu Functions ................................................... 4-5
RAC Plus I Additional Features ............................................ 4-10
Troubleshooting ......................................................... 5-1
Frequently Asked Questions ................................................... 5-2
Appendix ........................................................ A-1
RAC Plus I Specifications ...................................................... A-2
Power Connection Wiring ...................................................... A-3
Glossary ........................................................ A-4
Vehicle Calibration Record .................................................... A-6

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Quick Start Guide
The RAC Plus I DMI will allow you to accurately measure distance quickly
and easily. However, before you can do this a few basic steps must be taken
to ensure that you get the optimum performance from your instrument.
Step 1
Install your RAC and its distance sensor. Refer to Chapter 2 for detailed
instructions on this. If you would like to have the equipment professionally
installed, contact a garage or speedometer shop in your area.
Step 2
Calibrate your instrument. Refer to Chapter 3 for detailed instructions on
how this is done. Your RAC will not accurately measure distance unless
it is properly calibrated.
Step 3
Perform a test measurement with your vehicle. Once your RAC has been
calibrated, you should perform a test measurement over a known distance.
This will ensure that the instrument has been calibrated correctly.
To do a test measurement, drive to your starting point and stop. Turn on the
RAC and wait until zero is shown on the larger, upper display and CH is
shown on the smaller, lower display. Next, press the CH (count hold) button
to release the instrument from count hold and then drive the distance to be
measured. Stop and/or press the CH button once you reach the end of the
distance to be measured.
Step 4
Familiarize yourself with the features and options of the instrument that
you will be using. Refer to Chapter 4 for more detailed instructions on the
functions and procedures of the RAC Plus I.
Step 5
Practice. Before attempting to use the instrument on a job, be sure you are
comfortable with how to operate it.

RAC Plus I User’s Manual
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1-1
Chapter 1
Introduction
to the
RAC Plus I
Chapter 1 — Introduction to the RAC Plus I

RAC Plus I User’s Manual
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What is the RAC Plus I?
The JAMAR Technologies Road Analysis Computer (RAC) Plus I is an
accurate, easy-to-use distance measuring instrument (DMI) that uses state-
of-the-art microprocessor technology. It has been designed with features to
provide you with a versatile and functional instrument that can be learned
in a very short time.
Fig. 1.1 — RAC Plus I Distance Measuring Instrument

1-3
How does it work?
The RAC Plus I is installed in your car along with a distance sensor.
Distance sensors do the behind-the-scenes work of the RAC Plus distance
measuring instruments. Connected between your vehicle and the RAC Plus
head unit, these sensors read and modify the data coming from your vehicle
and send a signal to the RAC telling it when to count distance.
There are currently three types of distance sensors that are used with the
RAC Plus I – the AutoLink OBD sensor, the modular sensor and the mag-
nectic sensor.
Why are there three types? Because distance measuring instruments are
used by a wide variety of customers who often have different needs and in
a wide variety of vehicles that don't all work the same.
The simple breakdown of the three is that the AutoLink sensor is the new-
est and easiest to install (plug and play, no tools required), but that ease of
install trades a degree of accuracy. The magnetic sensor is the most precise,
but much more intensive to install than the AutoLink, while the modular
sensor has accuracy similar to that of the magnetic sensor and is somewhat
easier to install, but is not compatible with all vehicles.
The next chapter details how to install these various sensors into your
vehicle. If your already have a sensor installed, you may skip to Chapter 3
for information on calibrating your RAC.
Chapter 1 — Introduction to the RAC Plus I

RAC Plus I User’s Manual
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2-1
Chapter 2
Installation
Chapter 2 — Installation

RAC Plus I User’s Manual
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Before You Begin
The JAMAR RAC Plus I distance measuring instruments are very reliable.
However, there can be some external variables that could affect proper op-
eration and the ability to accurately measure distance traveled. By observing
a few simple precautions you will be able to eliminate potential problems.
• Do not install wires near any object that could cause stray pulses to
be picked up, such as the alternator, spark plugs or engine coil.
• Do not install the wires or sensor near any objects that will get hot,
such as the manifold. The installation wires or sensor can melt if they
are too close to a heat source.
• Do not install wires near any objects that could vibrate and cut the
wires.
• Tire pressure should be the maximum suggested by the tire manu-
facturer, typically 32-35 PSI cold. The tire should have ample tread
depth. Steel belted radial tires are highly recommended.
• Drive the vehicle 3 to 5 miles (depending on climate) to warm the
tires up to normal operating temperatures prior to calibrating your RAC.
Refer to Chapter 3, Calibration for more detailed instructions.

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Chapter 2 — Installation
Installing the OBD Distance Sensor
These instructions are for installing a RAC Plus I with an OBD Distance
Sensor. If you are installing a different type of sensor, skip this section.
The AutoLink allows connection between the On-Board Diagnostics (OBD)
connector in your vehicle and the RAC Plus Distance Measuring Instrument.
Note: Your RAC and vehicle should be turned off while plugging in the
AutoLink cables.
Step 1
Plug the large OBD cable attached to the AutoLink II into the vehicle
OBD connector. The OBD connector is typically found under your dash
near your steering wheel column.
Step 2
Connect the grey telephone-style cable from the AutoLink II to the
RAC Plus Power (PWR) port.
Fig. 2.1 – Plugging in to the OBD Port
Fig. 2.2 – Connecting the OBD Sensor to the RAC Plus I

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IMPORTANT: Note that the supplied grey telephone-style
cable is the ONLY cable that should be used. DO NOT use
any other cables that may have been provided with your RAC
as you may damage your RAC or the AutoLink.
Step 3
Now that the AutoLink II and the RAC are connected, start your
vehicle. Next, turn on the RAC and the AutoLink II LED lights will
begin flashing.
At this point, the Lock green LED will stay on and remain steady. A steady
green Lock LED indicates the AutoLink II is communicating with, and is
locked onto, the OBD signals coming from the vehicle computer.
The yellow “OBD Tx and Rx” LED lights confirm the transfer of informa-
tion between the OBD and the AutoLink II. Note that on 2010 and newer
vehicles the LEDs will flash very rapidly and may appear to be on constantly;
this is normal.
The self-adhesive mounting tabs and the tie wraps included can be used to
secure the OBD and the telephone-style cable as desired.
Step 4
Calibrate the RAC as described in Chapter 3. You are then ready to
start collecting data.
For Best Results
• OBD speed signals are generally not available below 1 MPH. As such, the
AutoLink II is not recommended for use where the vehicle may be travel-
ing at ‘creeping’ speed for any length of time. Recording short distance
nodes within a longer course using a stop and go method can result in less
accurate data. This is a function of extreme low speeds introduced during
starting and stopping. In these cases we recommend you use an alternative
sensor type, like a magnetic sensor, for higher accuracy.
• Note that while the vehicle is in motion the RAC and the AutoLink II
will have a small time lag while recording distances into memory. Also
note there will be a final buffered distance on the RAC once the vehicle is
fully stopped.
!

2-5
Chapter 2 — Installation
• After using your RAC, you should turn off the RAC while your vehicle is
not being used. Power consumption of the RAC display, although minimal,
may drain your battery if the vehicle is idle for an extended time with the
RAC connected and turned on. This is particularly true if your battery is
in poor condition.
• The AutoLink II is turned on and off by the RAC’s power switch and
as such can be left connected to the OBD port while not in use. Note that
this was not the case with the original AutoLink I. The AutoLink I should
always be disconnected from the OBD when not in use.

RAC Plus I User’s Manual
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Installing the Modular Distance Sensor
Note: These instructions are for installing a RAC Plus I with a Modular
Distance Sensor. If you are installing a different sensor, skip this section.
1. Find a location under the vehicle
dashboard that will allow fairly easy
access to the MDS. Do Not mount the
MDS on the heater ducts or where the
heater vents will blow directly onto it.
Attach the MDS using the nylon ties or
Velcro provided, as shown in Fig. 2.3.
2. Locate the 2 wires coming from the Vehicle’s Speed Sensor (VSS).
• On most Ford and Chrysler pick-up trucks, the best place is on the
rear end differential housing using the rear ABS signal.
• On GM pick-up trucks, the best place is the VSS at the transmission.
• On many vehicles (both trucks and autos) you can go to the cruise
control signal or to the vehicle ECU which is often located under the
dashboard.
(Note: Vehicle wiring changes from year to year
and model to model. For technical support in lo-
cating the vehicle speed signal wire call JAMAR
at 215-361-2244. Your local Auto/Truck dealer
can also usually tell you where the VSS can be
located on your vehicle.)
3. Route the red and black end of the 20’ grey VSS
cable through the firewall. This can usually be done by using an existing
rubber grommet where other wires pass through the firewall. If you cannot
locate an existing hole, CAREFULLY drill a small hole large enough for
both the VSS cable and the +12Volt/Ground wires. EXTREME CAUTION
must be taken to insure you do not drill into anything mounted on the op-
posite side of the firewall or cut any existing wiring.
All wires and the
MDS itself should be
kept away from heat
sources that could
cause melting.
Fig. 2.3
MDS Mounted Under Dash

2-7
Chapter 2 — Installation
Use the cable ties provided while routing the cable to the location for getting
the speed signal that you previously identified. Attach the red wire of the
VSS cable to the high-speed signal wire of the vehicle’s speed sensor using
the tap splice connectors provided. The black wire is for optional use with
vehicles made before 2002. In these vehicles, it should be connected to the
low speed signal wire of the vehicle’s speed sensor or chassis ground. If you
are unsure which wire from the VSS is the high-speed signal and which is
the low-speed signal, pick one and connect the red wire to it. If the RAC
counts when the vehicle moves, you are good to go. If not, connect the red
wire to the other wire from the VSS.
NOTE: The tap splice connectors are supplied for convenience for ini-
tial installation. However, we recommend that once the installation is
completed and you have verified the instrument is working properly,
remove the tap splice connectors and solder the connections. Insulate
using electrical tape or silicone.
4. Plug the connector of the VSS cable
into the hole labeled VSS Input located
on the right side of the MDS, as shown
in Figure 2.4.
5. Route the black DMI cable from the
MDS to the desired instrument location. This will usually be routed between
the doorpost and the dashboard. Make sure the cable will not be pinched
when closing the door. If the instrument is going to be mounted to the front
of the dashboard, you may want to bring the cable straight up the front of
the dash. There is adequate cable length
to allow mounting the DMI in any de-
sired location inside the vehicle. Plug
the cable into the MDS jack labeled To
DMI, as shown in Figure 2.5. It does
not matter which end of the cable is
plugged into the MDS or DMI.
6. Route the Red (+12 Volts) and Black (Ground) power cables directly to
the vehicle’s battery. This can be done using the same feed through loca-
tion that was used for the VSS Cable. If, out of convenience, you elect to
obtain the +12VDC and ground from a fuse panel or other location under
the dashboard, make sure it is a constant 12 volt source and not one that
Fig. 2.4 –VSS Plug-in
Fig. 2.5 – DMI Plug-in

RAC Plus I User’s Manual
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is switched off with the ignition key.
We also recommend the circuit should
have as few devices as possible to avoid
voltage fluctuations from Turn Signals,
Brake Lights, etc. Plug the power cable
into the hole labeled Power on the
MDS, as shown in Figure 2.6.
Adjusting the Vehicle Speed Sensor Pulse Rate
The signal pulses coming from the vehicle speed sensor are generated for
use by the vehicle’s computer, engine/transmission control, fuel manage-
ment, ABS brakes, etc. The pulse rate can vary from 4,000 to in excess of
100,000 pulses per mile. The MDS will condition and amplify these pulses
for use by the DMI. Since the higher
pulse rates are not required for accu-
rate distance measurements, the MDS
incorporates a divider circuit to reduce
the pulse rate. This is done by adjusting
the rotary switch on the front of the
MDS, as shown in Figure 2.7.
The adjustments go from 1 to 1 (1 pulse
into the sensor, 1 pulse out) through
64 to 1 (64 pulses into the sensor, 1 pulse out). Although your particular
vehicle may vary, generally Chrysler and Ford vehicles use a 4 to 1 ratio
(position 4 on the switch) while General Motors vehicles use a 16 to 1 ratio
(position 16 on the switch).
To adjust the ratio, use a small screwdriver to turn the switch to align it
with the number you want. Note that the switch is at the '1' position when
switch is turned fully counterclockwise. It is at the ‘Test’ position when the
switch is turned fully clockwise.
The Tap Test positions are explained in the troubleshooting section on page
3-4. You may need to adjust the ratio again based on the results of the cali-
bration procedure described in Chapter 3. Any time you change the pulse
ratio, you will need to re-calibrate the DMI.
Once you have installed the MDS, install your RAC Plus using the instruc-
tions on page 2-15.
Fig. 2.6 –Power Plug-in
Fig. 2.7
Rotary Switch Adjustment

2-9
Chapter 2 — Installation
The number of pulses per mile from a vehicle will vary with the make and model.
Your calibration factor should be between .500 and 1.200. If not, adjust the
rotary switch then recalibrate to reach a calibration number within this range.
If the speedometer does not respond to
vehicle movement, simply switch the
RED wire to the other VSS wire.
Most vehicles should have a 2-wire output from the VSS.
Dodge & Ford trucks may have the VSS located on top of the rear end housing instead of at
the transmission. It will normally be a 2-wire output, small gauge wire.
Connect the red wire of the long 20’ VSS cable to the high-speed signal wire of the vehicle’s
speed sensor. (The black wire is for optional use with vehicles made before 2002.) Crimp-on tap
splice connectors are supplied for convenience on initial installation. However, we recommend
removing the tap splice connectors and reconnecting using wire to wire solder once you are
sure all connections to the VSS are proper. Insulate with sealant/electrical tape as needed.
Fig. 2.9 –MDS Installation Diagram
Vehicle Speed
Sensor (VSS)
Fire
Wall
Fire
Wall
Tap Splice
Connector
Battery
RAC Connector
Ground Black
+12 VDC Red
High Speed Signal
Low Speed Signal
+–
The black wire is is for
optional use with vehicles
made before 2002.
Red
Black
Filter Toggle
As a default, the Filter toggle should be set to ‘Filter
Off’. However, on some vehicles there is ‘noise’ on
the speed sensor line that causes the RAC to count
up while the vehicle is not moving. The filter toggle
should be flipped to ‘Filter On’ in these cases.
Fig. 2.8 –
Filter Toggle
Filter toggle should always be OFF unless
you are getting ‘noise’ on the speed sensor
line, which causes the RAC to count while
the vehicle is not moving.

RAC Plus I User’s Manual
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Installing the Magnetic Distance Sensor
Note: These instructions are for installing a RAC Plus I with a Magnetic
Distance Sensor. If you are installing a different sensor, skip this section.
For the installation you will need the Magnetic Sensor Kit shown below.
A – Magnets
B – Epoxy
C – Zip Ties
D – Mounting Bracket
E – Hardware Kit
F – Magnetic Sensor
G – Extension Cable
and the Vehicle Installation Kit shown below.
H – Terminal Block
I – Power Cable
J – Ground Cable
K – DMI Connector Cable
L – Velcro
M – Zip Ties
F
G
D
B
A
E
C
Fig. 2-10
Fig. 2-11
H
I J
K
L
M