REAR LIGHTING
TAIL LAMPS AND REAR LICENSE PLATE LAMPS
Circuit A3 from fuse 5 in the Power Distribution
Center (PDC) connects to a bus bar in the fuse block
which feeds circuit L7. Fuse 15 in the fuse block pro-
tects circuit L7.
The headlamp switch has three positions: ON,
PARK (parking lamps) and OFF, plus a dimmer
switch. When the headlamp switch is in the PARK or
ON position, the switch connects circuit L7 to circuit
L90. From the headlamp switch, circuit L90 branches
to power the front parking lamps and rear tail
lamps, side marker lamps, and rear license plate
lamps.
GROUND CIRCUIT
Circuit Z1 provides a ground for the parking lamps,
tail lamps, and rear license plate lamps.
HELPFUL INFORMATION
²If the vehicle is equipped with factory installed
trailer tow, circuit L90 splices to the trailer tow har-
ness.
²Check fuse 5 in PDC.
²Check fuse 15 in the fuse block.
²When the headlamp switch is in the PARK or ON
position, circuit L7 also connects to circuit E2. Cir-
cuit E2 continues through fuse 19 in the fuse block.
Circuit E2 powers the illumination lamps.
STOP LAMPS AND CHMSL LAMPS
Circuit L9 from fuse 4 in the Power Distribution
Center (PDC) connects to the stop lamp switch.
When the operator depresses the brake pedal, the
stop lamp switch closes and connects circuit L9 to
circuit L50. Circuit L50 connects to the stop lamps
and Center High Mounted Stop Lamps (CHMSL).
Circuit Z1 provides a ground for the stop lamps and
CHMSL lamps.
HELPFUL INFORMATION
²Check fuse 4 in the PDC.
²Check for continuity across the stop lamp switch
when it is closed.
BACK-UP LAMPS
In the START or RUN position, the ignition switch
connects circuit A1 from fuse 6 in the Power Distri-
bution Center (PDC) to circuit A21. Circuit A21 feeds
a bus bar in the PDC that powers circuit F12
through fuse 11.
Circuit F20 supplies power to the back-up lamp
switch. On automatic transmission equipped vehicles,
the back-up lamp switch is part of an assembly that
includes the PARK/NEUTRAL position switch. When
the operator puts the transmission in REVERSE, the
back-up lamp switch connects circuit F20 to circuit
L10. Circuit L10 feeds the back-up lamps. Circuit Z1
provides ground for the back-up lamps.
HELPFUL INFORMATION
²Check fuses 6 and 11 in the PDC.
²Check for continuity across the back-up lamp
switch when it is closed.
DIAGRAM INDEX
Component Page
Back-Up Lamps........................8W-51-4, 5
Back-Up Lamp Switch.....................8W-51-2
Center High Mounted Stop Lamps (CHMSL).......8W-51-3
Fuse 15 (Fuse Block)......................8W-51-2
Fuse 4 (PDC)...........................8W-51-3
Fuse 6 (PDC)...........................8W-51-2
Fuse 7 (PDC)...........................8W-51-2
Fuse 11 (PDC)..........................8W-51-2
Headlamp Switch.........................8W-51-2
Ignition Switch..........................8W-51-2
License Plate Lamp.......................8W-51-3
Park/Neutral Position Switch.................8W-51-2
Side Marker Lamps.....................8W-51-4, 5
Stop Lamp Switch........................8W-51-3
Tail/Stop Lamps........................8W-51-4, 5
Turn Signal Lamps......................8W-51-4, 5
J8W-51 REAR LIGHTINGÐXJ VEHICLES 8W - 51 - 1
