Page
2 of 2
Hayes
Lemmerz International, Inc.
INSTALLATION AND
OPERATING INSTRUCTIONS
for the
81741A all
Electronic Brake Controller
II. CONTROL MODULE WIRING
WARNING
ALL CONTROL MODULE WIRES MUST BE CONNECTED OR THE CONTROL MODULE WILL NOT
OPERATE PROPERLY IN ALL MODES. FAILURE TO DO SO IS LIKELY TO CAUSE A LOSS OF
TRAILER BRAKES.
A. The control module has four
color coded wires. Wiring of the module will involve the black, white, red and
blue wires. It is recommended that all connections be made with insulated
solderless crimp style connectors.
1. WHITE GROUND
WIRE is supplied with a ground lug and must be affixed to grounded metal
part of the dash or vehicle firewall.
WARNING
IF NOT PROPERLY GROUNDED, THE CONTROL MODULE AND/OR INDICATOR LIGHT WILL NOT
OPERATE CORRECTLY. FAILURE TO GROUND WILL CAUSE ERRATIC TRAILER OR NO TRAILER
BRAKES AND NO INDICATOR LIGHT.
2. BLUE
BRAKE WIRE must be connected directly to the trailer brake wire.
3. RED
STOPLIGHT WIRE powers up the electronic circuit of the control module and
must be connected to the non-powered wire of the stoplight switch.
NOTE: To locate the
non-powered wire it may be helpful to use a 12 volt test light. Connect one test
light lead to ground and the other lead to one of the two stoplight switch
terminals. The non powered wire is the one which turns the test light on when
the brake pedal is depressed and off when the brake pedal is released.
NOTE- 1989-91 Ford Bronco,
Econoline, F Super Duty & F150-350 series: The red stop light wire must
splice into the turn signal connector harness. Splicing directly into the stop
light switch may cause interference with other electrical systems.
NOTE - As of 1992, all Ford
vehicles with the trailer towing package are provided with a stop light wire for
the control module to splice into.
WARNING
SOME VEHICLES ARE EQUIPPED WITH SEPARATE SWITCHES FOR TRANSMISSION CONVERTER
AND CRUISE CONTROL. BE SURE THE RED WIRE IS CONNECTED TO THE NON-POWERED SIDE OF
THE STOP LIGHT SWITCH. IF NOT PROPERLY CONNECTED TO THE STOP LIGHT SWITCH, THE
INDICATOR LIGHT AND TRAILER BRAKES WILL NOT OPERATE IN CONJUNCTION WITH THE
VEHICLE FOOT PEDAL.
4. BLACK WIRE
is the positive voltage power supply line. Using a 12 gauge wire, connect
through a 20 amp self resetting circuit breaker to the positive side at the
battery (preferred connection) or on some vehicles to the starter solenoid
(alternate connection) (Fig. 5). Route the wire through a
grommeted hole in the firewall to the black wire of the control module. IT IS
ADVISABLE TO ROUTE THIS WIRE AWAY FROM THE RADIO ANTENNA TO REDUCE ANY POSSIBLE
AM RADIO INTERFERENCE.
WARNING
THE POWER SUPPLY WIRE MUST BE A COMPLETELY SEPARATE CIRCUIT FROM THE BATTERY OR
STARTER SOLENOID TO THE CONTROL MODULE. DO NOT ATTACH THE POWER SUPPLY WIRE TO
ANY TOW VEHICLE WIRING USED FOR OTHER ACCESSORIES OR TRAILER CIRCUITS. IMPROPER
CONNECTION WOULD LIKELY CAUSE INTERFERENCE OR OVER-LOADED CIRCUITS RESULTING IN
LOSS OF TRAILER BRAKES.
III.
ADJUSTING
THE PENDULUM ASSEMBLY AND PRELIMINARY TRAILER BRAKE SYSTEM CHECK OUT
After the brake controller has been
mounted and all four wires have been electrically connected according to
Sections I and II, the Pendulum Assembly must be adjusted for each specific
installation.
WARNING
PENDULUM ASSEMBLY MUST BE ADJUSTED CORRECTLY (FIG. 9) OR
CONTROL MODULE WILL NOT OPERATE SATISFACTORILY. IF IMPROPERLY ADJUSTED IT COULD
CAUSE DELAYED OR NO TRAILER BRAKES AND NO INDICATOR LIGHT (FIG.
7) OR GRABBING OR PULSING TRAILER BRAKES AND STEADY ILLUMINATED INDICATOR
LIGHT (FIG. 8)
A. Connect the trailer to the tow
vehicle for this adjustment. If a load leveling hitch system is used it should
be operational or "ready to go on the road". Locate the tow vehicle
and trailer on a flat level surface. Make sure the tow vehicle stop lamps are
operating correctly, and disconnect all (with possible exception of ground)
electrical connections between the tow vehicle and the trailer.
B. Adjust the Load Control Knob (Fig
6) to its maximum brake position (fully clockwise).
C. Depress the brake pedal far
enough to turn on the vehicle stop lamps. Hold this position.
D. Pull the Pendulum Leveling Arm
(Fig 6) toward the indicator light The indicator light
should illuminate brightly (red).
E. Push the Pendulum Leveling Arm
(Fig 6) away from the indicator light until the indicator
light just reaches minimum brilliance. The leveling arm should be approximately
straight down. Repeat steps D and E several times to make sure the indicator
lamp has just reached minimum brilliance.
F. Release the brake pedal. The
pendulum assembly is now initially adjusted A readjustment may be necessary if
the loading of either the tow vehicle or trailer causes a considerable change in
the tow vehicle front to rear position. Also a further readjustment may be
desired during Road Test and Performance Adjustments Section IV.
G.
Move the
control module Manual Lever (Fig 6) to the left and observe
the control module indicator light become increasingly brighter as the manual
lever is moved.
H. If the indicator light does
not illuminate the tow vehicle has a short to ground in the trailer brake
circuit, check and repair as necessary.
J. Electrically connect the
trailer to the tow vehicle and check the trailer for stop lamps operating
correctly: repair as necessary trailer wires, bulbs, ground connections and
trailer to tow vehicle connector.
K. Repeat Step G.
If the indicator light does not illuminate or glows dimly check and repair as
necessary, the trailer brake magnets and trailer brake circuit (including the
trailer to tow vehicle connector) for a short to ground. IF A SHORT OCCURS IN
THE TRAILER BRAKES, PLUG OR TRAILER WIRING, THE CONTROL MODULE CIRCUITRY WILL
SHUT DOWN AND THE INDICATOR LIGHT WILL NOT ILLUMINATE OR WILL GLOW EXTREMELY
DIM. THIS CONDITION WILL REMAIN UNTIL THE SHORT IS LOCATED AND REPAIRED.
NOTE: It is normal to hear the
trailer brake magnets "hum" while testing the controller or otherwise
while operating the trailer brake system.
L. Move the control module
Manual Lever to the left and observe the trailer stop lights come on . The
trailer stop lights must illuminate when the manual lever is moved to the left.
If the trailer stop lights do not illuminate, recheck trailer wires, bulb ground
connections at the bulbs and trailer to tow vehicle connector also check the red
wire connection at the brake controller for being connected to the non-powered
side of the stop lamp switch.
IV. ROAD TEST AND PERFORMANCE
ADJUSTMENTS
Optimum tow vehicle/trailer
braking occurs just short of skidding the trailer wheels. "SKIDDING TRAILER
WHEELS CAN CAUSE LOSS OF DIRECTIONAL STABILITY OF THE TRAILER AND POSSIBLY THE
TOW VEHICLE." In order to obtain optimum trailer braking, the trailer
brakes must be properly maintained and adjusted. Trailer electric brakes are not
self-adjusting.
A. Control module setting for
optimum trailer brakes.
1. Adjust the load
control knob (Fig 6) to the midrange setting (center of knob
travel).
2. At a moderate
speed (20 mph or less) push on the tow vehicle brake pedal in a normal manner.
With the load control knob set in the mid-range setting, a firm braking action
should occur. If more trailer braking is required, turn the load control knob
(clockwise). If less trailer braking is required, turn the load control knob
(counter clockwise). The indicator light should illuminate from dim to brighter
during the stop and back to dim after stop is completed.
3. At a moderate
speed (20 mph or less) energize the manual lever slowly to the left. A much
harder stop can always be obtained as the manual lever is not affected by the
load control setting. The indicator light should illuminate from dim to bright
during the stop.
B. Readjustment of Pendulum
Leveling Arm: If the conditions described below occur, refer to Figures
7, 8 and 9 for the affects of Pendulum Leveling Arm misadjustment.
1.
Pendulum leveling arm too far to rear (Fig 7):
-
No indicator light
-
Delayed braking
-
No braking
2.
Pendulum leveling arm too far toward front of control module (Fig
8):
3.
Pendulum leveling arm adjusted correctly (Fig. 9):
V. BRAKING ON HILLS
When properly adjusted, the control
module will allow a slightly greater amount of trailer braking going downhill
and slightly less trailer braking going uphill. Normally, no control module
readjusting is needed for towing in the hills.
VI. TRAILER BRAKING WITH 4-WAY
FLASHERS OPERATING
A. With the control module
properly adjusted, the indicator light will flash with the 4-way flasher lights
but will not operate the trailer brakes.
B. If the control module is
not adjusted correctly, the trailer brakes can possibly pulse with 4-way flasher
lights (Fig. 8)
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