Thunder Heart EA4250D User manual

Owner’s Manual
Electronic Harness Controller
P/N EA4250D
Thunder Heart Performance Corporation MANUAL P/N EI4250
120 Industrial Drive Revision 5/26/11
White House, TN 37188
www.thunder-heart.com

TABLE OF CONTENTS
CHAPTER 1 INTRODUCTION ...............................................1
1.1 General Information....................................................................1
1.2 Special Tools Required..............................................................2
1.3 Connector Assembly..................................................................4
1.4 EHC Component Overview........................................................5
CHAPTER 2 SYSTEM INSTALLATION.................................6
2.1 Finding a Suitable Location for the Electronic Harness Control
Module.................................................................................................6
2.2 Trial Fitment of the Harness to the Bike.....................................7
2.3 H-D 1996-2003 Hand Control Connections ...............................8
2.4 Rear Lighting Options.................................................................9
2.5 Harness Assembly .....................................................................9
CHAPTER 3 INDICATORS AND INSTRUMENTATION ......10
CHAPTER 4 OPERATION....................................................11
4.1 Diagnostics...............................................................................11
4.2 Turn Signals .............................................................................11
APPENDIX A FREQUENTLY ASKED QUESTIONS ...........11
APPENDIX B OPTIONAL AND REPLACEMENT PARTS...12
APPENDIX C TROUBLESHOOTING...................................12
APPENDIX D WIRING TABLES AND DIAGRAMS .............13
CONTACTING THUNDER HEART PERFORMANCE CORP.
Mailing Address................................120 Industrial Drive
White House, TN 37188
Shipping Address .............................120 Industrial Drive
White House, TN 37188
Phone ...............................................615-672-8811
Fax....................................................615-672-1353
Tech Support [e-mail]
Website.............................................www.thunder-heart.com

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CHAPTER 1 INTRODUCTION
1.1 General Information
The Electronic Harness Controller consolidates all of the electronic functions
of a motorcycle (with the exception of instrumentation and engine
management) into one, easy-to-hide system. The Electronic Harness
Controller avoids the wiring “bird’s nest” of other systems so you spend less
time wiring your bike…and more time riding!
Perfect for split tank bikes, the Electronic Harness Controller system includes
a self-diagnostic electronic harness controller, un-terminated “fantail”
harness, shrink tubing, and all necessary connectors, a comprehensive
instruction and troubleshooting manual for a durable, professional
installation.
The information included in this manual is intended to provide a guideline for
installing the Electronic Harness Controller system on your motorcycle.
However, each motorcycle is different. Due to the “universal” nature of this
system, a certain level of technical skill is required to assure a complete,
trouble-free installation.
Please read through this entire manual before attempting any part of the
installation. If you are uncomfortable with the level of skill required to
complete the installation of this system, either contact a Thunder Heart
Performance technical specialist, or hire a professional to complete the install
for you.
Note: The EA4250C and EA4250D differ in the function of the turn signals when
the brakes are applied. The EA4250C flashes the turn signals three times
prior to keeping them illuminated for 30 seconds, or until the brakes are
released (whichever comes first). It can only be installed on bikes with a
center taillight. The EA4250D does not flash the turn signals when the brakes
are applied. It can be installed on bikes with and without a center taillight.

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1.2 Special Tools Required
Most of the installation of the Micro Harness Controller can be completed
with basic hand tools. However, a few special tools make the job much
easier:
xAheat gun (such as the unit shown in Figure 1) is required to shrink
the heat shrink tubing onto the harness. The heat gun makes quick
work of shrinking the tubing, as it provides a broad, even source of
heat. No other means of shrinking the tubing is recommended.
Figure 1 – Heat Gun
xA good-quality wire-crimping tool is also required. The “W” style
(shown in Figure 2) is available at www.digikey.com (Digikey part
number WM9999-ND).
xThe AMP style (shown in Figure 3), while considerably more
expensive, will produce better results. The AMP style is
recommended if you plan on wiring many bikes using the AMP
connectors included with the Electronic Harness Controller system.
Figure 2—“W” crimping tool

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Figure 3—“AMP” crimping tool
xAmulti-meter is useful for diagnosis. A common “test light” is OK,
but a test light will not tell you if you have a short to ground, or a
resistance problem. In other words, a pinched wire may provide
enough current for the test light, but not enough to power the horn,
ignition, etc. A multi-meter allows you to check current, and you can
check the suspect circuit for any grounding issues.
Figure 4—Multi-Meter; useful for circuit diagnosis

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1.3 Connector Assembly
The following information highlights proper assembly procedures for the AMP
connectors included with the Micro Harness Controller system:
1. Strip approximately 3/16” of insulation off of the end of the wire to be
terminated.
Figure 5—Proper wire strip amount
2. Clip a terminal from the supplied “tree” of terminals.
3. Using either a “W” or an “AMP” tool, crimp the terminal onto the end of
the wire. The following figures show examples of “good” and “bad”
crimps:
Figure 6—Good Crimp; insulation retained by outside tabs, conductor
retained by inside tabs
Figure 7—Bad Crimp; too much wire stripped; strands exposed outside
of terminal
Figure 8—Bad Crimp; too much wire stripped; insulation not retained
by outside tabs

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4. Insert the wire through the blue seal into the connector body until you
hear a “click.” Gently pull on the wire to ensure that the terminal is fully
engaged in the housing.
1.4 EHC Component Overview
Throughout this manual you will be referred to the various components of the
EHC system. Use the following figures to aid in component identification:
Figure 9—EHC Module Front Panel
Figure 10—EHC Module Rear Panel Components

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Figure 11—Handlebar Harness Connectors
Figure 12—Included Terminals
CHAPTER 2 SYSTEM INSTALLATION
2.1 Finding a Suitable Location for the Electronic
Harness Control Module
Split Tank Bikes
The Electronic Harness Controller (EHC) is designed to mount to the top
frame tube between the gas tanks. The black plastic mounting base is
molded to fit the tube radius and slotted to accept “zip tie” fasteners. The
EHC snaps onto the mounting base via three mounting tabs so that the
diagnostic instructions are visible with the dash removed.

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Saddle Tank Bikes
When using a saddle tank, an alternate mounting location must be found.
The most common areas are near the oil bag and under the transmission.
The mounting base may not fit in these locations. Zip ties can be used to
attach the EHC to its mounting location. If possible, the EHC diagnostic
instructions should face in a direction that will make them visible with little or
no disassembly for service. Care should be taken to keep the EHC a safe
distance from the exhaust system.
Note: Though the EHC module is moisture and vibration resistant, care should be
taken in mounting the EHC so that it is not subjected to excessive amounts
of vibration, heat, and moisture. The EHC should be mounted at least four
inches away from the engine to avoid radiating engine heat.
WARNING: FAILURE TO MOUNT THE ELECTRONIC HARNESS CONTROLLER,
WIRES, OR CONNECTORS AWAY FROM EXCESSIVE HEAT SOURCES
(SUCH AS THE ENGINE AND EXHAUST PIPES) MAY RESULT IN
FAILURE OF THE ELECTRONIC HARNESS CONTROLLER SYSTEM.
2.2 Trial Fitment of the Harness to the Bike
The following steps outline the process of trial fitting the harness to the bike.
The installer may experiment with different routings to achieve the best
results:
1. With the EHC mounted, plug the rear harness connector into the EHC.
Note: Each wire is labeled according to its function. Refer to the wiring tables and
diagrams in APPENDIX D. “Auxiliary Power” sources can be used to power
brake lights, license plate lights, etc.
2. Route each wire to its destination, but do not cut them yet. Keep wires
bundled together until they need to break off to their destination. Use
electrical tape to construct branch points and to temporarily attach the
harness to the bike while fitting is performed. Wires not used should be
terminated at the connector to prevent short circuits.
Tip: Try to minimize the number of branches from the main harnesses by
combining wires that branch off closely in one larger branch, as this will make
the heat shrink easier to apply later.
Tip: Remember to allow extra length for suspension movement or strain relief
when locating the harness-to-bike attachment points.
WARNING TAKE CARE TO ROUTE THE HARNESS AWAY FROM SHARP EDGES
OR SURFACES THAT MAY PINCH THE HARNESS. ROUTE THE
HARNESS AWAY FROM SOURCES OF HIGH HEAT, SUCH AS THE
ENGINE AND EXHAUST SYSTEM.
3. Start again at step 1 for the front harness and the left/right control
harnesses.
Note: For 1996-2003 hand controls, see Section 2.3.

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Note: The “horn” and “auxiliary power” circuits are found on both the front and rear
harness connectors to allow for different mounting locations. Use the most
convenient one for the horn. Both “auxiliary power” circuits may be used as
needed.
4. When all the wires are routed and the harnesses are temporarily
attached at their mounting points, cut the excess length from the ends of
the wires, leaving them approximately 3” too long for final fitment.
2.3 H-D 1996-2003 Hand Control Connections
Starting in 1996, Harley spliced the power wires of both the left turn signal
and the horn, and the right signal and the brake switches together.
Figure 13—H-D 1996-2003 Hand Control Harness
Figure 14—H-D 1996-2003 Hand Control Wire Splice
When using these hand controls, you have two options:
xUse the existing H-D harness with splice in place, and not use the
“left turn signal switch power” and “right turn signal switch power”

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circuits of the EHC. (Note: Diagnostic functions will not work for the
left and right turn signals, as they will be powered from the Horn and
Brake Light Switch circuits). See Appendix D, Wiring Tables and
Diagrams.
xRemove the splice in the H-D handlebar controls harness, determine
which Orange w/White Stripe wire goes to the turn signal and horn or
brake switch, and wire these independently to their respective
circuits on the EHC. See Appendix D, Wiring Tables and Diagrams.
2.4 Rear Lighting Options
The EHC accommodates two rear lighting configurations. Two wiring
diagrams in Appendix D detail the wiring for each configuration:
Note: *Turn signals will always function as turn and brake lights*
xTurn signals functioning as a turn signal and brake light (see Figure
21)
xTurn signals functioning as a turn signal, brake light and tail light
(this option requires dual filament turn signal housings)(see Figure
22)
2.5 Harness Assembly
After the harness is trial fitted to the bike, the next steps highlight the
installation of heat shrinkable tubing to the harness:
1. Remove the harness from the bike.
2. Starting from the rear harness connector at the EHC, cut a piece of heat
shrink tubing long enough so that it extends about 1” past the first branch
in the harness. This extra length will allow the tubing for the branches to
slide into the main tubing as shown in Figure 15. This crates a smooth
transition to the branches.
Figure 15 – Proper Heat Shrink Overlap
3. When the tubing section ends at a termination point (connector or
terminal), slide a long piece into the main tubing and then cut it at the
end of the wire (removing the last 1/4” or so of the wire as well.

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4. With the heat shrink tubing installed, use a heat gun to shrink the tubing.
Start at the EHC connector and work to the other end.
5. Start to re-fit the harness to the bike by plugging in the rear harness
connector into the EHC.
6. Move along the harness and attach it to the bike where necessary.
7. Cut the ends of the harness to length (remember to allow room for
movement and strain relief).
8. Strip the ends of the harness.
9. Attach the terminals to the wire ends and use a heat gun to shrink the
strain reliefs.
Note: If no colored shrink tubing is attached to a terminal, use the black 1” pieces
supplied with the kit.
10. Repeat the process for the other three harnesses.
CHAPTER 3 INDICATORS AND INSTRUMENTATION
Indicator Options
The EHC is designed to control LED-type dash indicators. LEDs are brighter,
vibration resistant, more power efficient, usually don’t need to be replaced,
and are generally easier to mount on a custom bike. When a Thunder Heart
Performance LED indicator panel is used (such as P/N RSE4088), simply
find a suitable mounting location and plug the supplied 16” cable (72” cable is
optional P/N RSE4145) into the EHC.
Figure 16—EA4088
Speedometer Options
Thunder Heart also offers adapter harnesses for use with Dakota Digital
speedometers (built-in indicators). See Appendix B, “Optional and
Replacement Parts” for the correct harness for your application.

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CHAPTER 4 OPERATION
4.1 Diagnostics
When the bike is first powered up, check the diagnostic LEDs on the label
side of the EHC. If any of the LEDs are illuminated, the circuit whose label is
next to the LED is either shorted to ground, or overloaded. This is generally
due to a pinched bare wire, a faulty component, or use of components with
excessive current draw (for example, too many lights on the headlight
circuit).
Note: The current rating of the circuit protectors are affected by temperature, so
care should be taken not to mount the EHC too close to the engine or
exhaust system.
Note: Always turn the power off after an LED has been activated to resent the
protection circuit.
If no LEDs are lit up, but the turn signals and dash indicators do not function
properly, check that the EHC main ground wire (J4, Pin 4), has a good, solid
connection to the chassis ground (such as the battery negative terminal or a
paint-free boss on the frame).
4.2 Turn Signals
Table 1 – Summary of commands and the corresponding turn signal
function
APPENDIX A FREQUENTLY ASKED QUESTIONS
I can’t read the pin numbers on the connectors.
Try rubbing a crayon or pencil across the back face of the connector. This
will cause the numbers to stand out more clearly. Also, the number “1”
terminal is designated by a rib on the side of the connector.
I am not using standard-type handlebar controls. How do I wire the
“right” and “left” harness connectors?
Even if you use discrete switches instead of handlebar controls, the wiring
diagram is the same. Since most of the switches are two-terminal types, the
wire color on the diagram is not important. For example, if you were to
reverse the horn switch terminals, the harness will still function properly.
Command Function
First command (left or right) Flash 10 times, then cancel
Second command (same side) Cancel
Second command (opposite side) Cancel current sequence, flash opposite side 10
times, then cancel
Left and right side simultaneousl
y
Flash all signals continuously (hazard function)

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Three-terminal switches such as the dimmer switch must be wired as shown
for proper operation.
I am not using a “kill” switch. How do I wire the right handlebar
harness?
You must use a “kill” switch. The kill switch is an extremely important safety
device and should never be removed from the bike.
Why does my headlight work, but not the turn signals?
You may have a missing ground connection. The EHC must be grounded
through the right handlebar connector using the supplied black wire to a good
chassis ground.
What if I am using handlebar controls from a 1996-2003 motorcycle?
Different wire identifications were used on 1995-and-earlier motorcycles than
1996-2003 motorcycles. See Section 2.3 and Appendix D for more
information.
APPENDIX B OPTIONAL AND REPLACEMENT PARTS
Table 2—EHC Optional and Replacement Parts
Component Thunder Heart P/N Notes
Starter Relay E2206 Also available at most auto parts
stores under Ford P/N F5TZ-14N089-B
EHC Module EA4200 Replacement
LED Indicator Panel (custom bikes) EA4088 Optional
Incandescent Lamp Indicator Kit (95-earlier H-D) EA4091 Optional
LED indicator Kit (96-later H-D) EA4091-96 Optional
16" Indicator Cable E4145 Included with RSE4088
72" Indicator Cable E4145 Optional
APPENDIX C TROUBLESHOOTING
SYMPTOM POSSIBLE CAUSE SOLUTION
Turn signal flashes rapidly LED Turn signal burned out or defective Replace LED bulb assembly
Turn signal not wired correctly Correct wiring per instructions
Poor connection Fix connection
Bike does not start Dead battery Charge Battery
Faulty Starter Relay Replace Starter Relay

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APPENDIX D WIRING TABLES AND DIAGRAMS
Table 3—Front Harness Connector Pin Assignments
PIN FUNCTION COLOR AWG
1 AUXILARY POWER RED 18
2 TURN SIGNAL, LEFT FRONT PURPLE 18
3 LOW BEAM YELLOW 18
4 HORN YELLOWw/BLACK STRIPE 18
5 TURN SIGNAL, RIGHT FRONT BROWN 18
6 HIGH BEAM WHITE 18
Table 4—Left Handlebar Connector Pin Assignments
PIN FUNCTION COLOR (pre-1996) AWG COLOR (1996-2003) AWG
1 LOW BEAM (FROM SWITCH YELLOW 18 YELLOW 18
2 HOR SWITCH POWER ORANGE 18 ORANGEw/WHITE STRIPE 18
3 DIMMER SWITCH POWER BLUE 18 BLUE 18
4 HIGH BEAM (FROM SWITCH WHITE 18 WHITE 18
5 LEFT SIGNAL POWER GREEN 18 ORANGEw/WHITE STRIPE* 18
6 BLOCK-OFF-PIN N/A N/A N/A 18
7 HORN (FROM SWITCH) BLACK 18 YELLOWw/BLACK STRIPE 18
8 BLOCK-OFF-PIN N/A N/A N/A N/A
9 FROM LEFT SIGNAL SWITCH VIOLET 18 WHITEw/PURPLE STRIPE 18
*Not required for 1996-2003 partial diagnostic method
Table 5—Right Handlebar Connector Pin Assignments
PIN FUNCTION COLOR (pre-1996) AWG COLOR (1996-2003) AWG
1 RIGHT SIGNAL SWITCH POWER GREEN 18 ORANGEw/WHITE STRIPE* 18
2 BRAKE SWITCH POWER ORANGE 18 ORANGEw/WHITE STRIPE 18
3 KILL SWITCH POWER GREY 18 GREY 18
4 GROUND (TO CHASSIS) BLACK 18 BLACK 18
5 START RELAY (FROM SWITCH) BLACK 18 BLACKw/RED STRIPE 18
6 COIL + (FROM KILL SWITCH) WHITE 18 WHITEw/BLACK STRIPE 18
7 BLOCK-OFF-PIN N/A 18 N/A N/A
8 FROM RIGHT SIGNAL SWITCH BROWN 18 WHITEw/BROWN STRIPE 18
9 BRAKE LIGHT (FROM SWITCH) RED 18 REDw/YELLOW STRIPE 18
*Not required for 1996-2003 partial diagnostic method
Table 6 – Rear Harness Connector Pin Assignments
PIN FUNCTION COLOR AWG
1 AUXILARY POWER (3A) RED 18
2 HORN YELLOWw/BLACK STRIPE 18
3 BRAKE LIGHT REDw/YELLOW STRIPE 18
4 TURN SIGNAL, RIGHT REAR BROWN 18
5 BRAKE SWITCH REDw/BLUE STRIPE 18
6 IGNITION SYSTEM (COIL +) WHITEw/BLACK STRIPE 18
7 TURN SIGNAL, LEFT REAR PURPLE 18
8 BRAKE SWITCH ORANGE 18
9 TAIL LIGHT BLUE 18
10 NEUTRAL SWITCH YELLOW 18
11 OIL SWITCH GREEN 18
12 STARTER SOLENOID GREEN 12
13 BATTERY + BLACK 12
14 IGNITION SWITCH RED 12
15 IGNITION SWITCH REDw/BLACK STRIPE 12

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Figure 17—Front Harness Wiring Diagram
“Wire Side” of Connector Shown

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Figure 18—Pre-1996 Hand Control Wiring Diagram
“Wire Side” of Connector Shown

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Figure 19—1996-2003 Hand Control Wiring Diagram (Partial Diagnostics)
“Wire Side” of Connector Shown