TITLE
44 Circuit Descriptions
CIRCUIT DESCRIPTIONS
Over View
The circuit wiring is broken down into three
basic parts, the Controller, under hood wiring,
and the plow wiring. A complete system sche-
matic and additional schematics with individual
circuits highlighted are included for your refer-
ence. A description of the layout of each cir-
cuit and its operation are described below.
30
86
87
87a
85
30
86
87
87a
RL2
RL1
LOW BEAM
RELAY
10A
HIGH BEAM
RELAY
RELAY BOX
ORANGE
3
YELLOW
4
GROUND
B+
J2
P2
GND
BLACK
RED
ACC. SW.
12 VOLT
BATTERY
-
+
SOLENOID
MOTOR
6 AWG RED
DOWN
SL1
S3
BROWN
BROWN 3
P1
J1
ORANGE 4
ORANGE S2
RIGHT
GREEN 5
GREEN
S1
LEFT
BLACK
GREEN
LED
POWER
CONTROLLER
DWG NO. 4126
POWER DISTRIBUTION / PROTECTION
Power Distribution / Protection
See DWG. NO. 4126
The power and ground for the controller are
supplied by connections to accessory switched
power and a suitable ground. Power from the ve-
hicles accessory terminal of the ignition switch
is connected to a 10 Amp fuse located on the
relay box in the under hood harness. The fused
power is connected to the headlight relays so
that the plow lights will not be on unless the igni-
tion switch is on. Fused power is also connected
to the controller so that it will not operate unless
power is on.
Spike suppression diodes should be mounted
across each solenoid to extinguish the voltage
spike that is generated when the coils are shut
off. These diodes are externally mounted on the
three hydraulic solenoids ( 1996 - 1999 replace-
ment plow harnesses have three mounted on
a circuit board in the harness ) and one on the
motor solenoid. There is additional protection
included in the controller for added spike sup-
pression, reverse battery protection, and special
current limiting. The controller is not field repair
-
able and should be replaced as an assembly if
found defective.