Turn Signals
During turn signal operation, power is supplied from the TURN fuse in
the IP fuse block when the ignition switch is in the RUN or the START
position. Power is supplied to CKT 139 (PNK) to the normally
closed TURN fuse contacts of the hazard switch through CKT 1508
(LT BLU) to the turn signal flasher. From the turn signal
flasher current flows through CKT 1697 (PPL) to the turn signal
switch. When the turn signal switch is in the LEFT TURN position,
voltage is supplied to the LT TURN (front) fuse via CKT 1414
(LT BLU/WHT) and to the LT TRN (rear) fuse via CKT 1418
(YEL/BLK). The LT TURN fuse supplies power to terminal A
of the LH park and turn signal lamp (and auxiliary turn signal lamp
on export) and the LH side marker lamp (except export) via CKT 2114
(LT BLU). The LT TRN fuse supplies power to terminal A
of the LH rear park and turn signal lamp (turn signal lamp on export)
via CKT 618 (YEL). The LH park and turn signal lamp (and auxiliary
turn signal lamp on export) receives ground through CKT 150
(BLK) to G111. The LH rear park and turn signal lamp (turn signal
lamp on export) receives ground through CKT 1350 (BLK) to
G450. The LH side marker lamp receives ground from CKT 2309
through terminal B of the LH park and turn signal lamp to
G111, via CKT 150 (BLK). The LH side marker lamp on the export
is directly grounded by CKT 150 (BLK).
When the turn signal switch is in the RIGHT TURN position, voltage is
supplied to the RT TURN (front) fuse via CKT 1415 (DK
BLU/WHT) and to the RT TRN (rear) fuse via CKT 1419
(DK GRN/WHT). The RT TURN fuse supplies power to terminal A
of the RH park and turn signal lamp (and auxiliary turn signal lamp
on export) and the RH side marker lamp (except export) via CKT 2115
(DK BLU). The RT TRN fuse supplies power to terminal A
of the RH rear park and turn signal lamp (turn signal lamp on export)
via CKT 619 (DK GRN). The RH park and turn signal lamp (and
auxiliary turn signal lamp on export) receives ground through CKT 250
(BLK) to G112. The RH rear park and turn signal lamp (turn signal
lamp on export) receives ground through CKT 1350 (BLK) to
G450. The RH side marker lamp receives ground from CKT 2309
through terminal B of the RH park and turn signal lamp to
G112 via CKT 250 (BLK).The RH side marker lamp on the export
is directly grounded by CKT 250 (BLK). The park side of the front
park and turn signal lamps do not illuminate due to the voltage drop
across the side marker lamps. During operation, the lamps illuminate
immediately. The lamps begin to flash when the current flow heats
the timing element in the flasher and repeatedly opens and closes
the circuit.
Hazard Lamps
During hazard operation, power is supplied from the HAZ LP fuse in the
underhood fuse block that is hot at all times through CKT 140
(ORN) to the HAZ LP fuse contact of the turn signal switch. When
the hazard switch is activated, power is routed to the turn signal
lamp flasher via CKT 1696 (GRY). From the turn signal flasher,
current flows through CKT 1697 (PPL) back to the turn signal
switch's now closed hazard contacts to the following circuits for
LH and RH turn signal operation:
Park, Side Marker and Rear License Lamps
For park/marker operation, power is supplied from the PARK LP fuse through
CKT 240 (ORN) to terminal F7 of the body relay block where
power is fed to the following components:
• | The park lamp relay coil |
• | The load side of the relay contacts |
For automatic operation, the body control module (BCM) grounds the park
lamp relay coil to feed CKT 74 (LT BLU) during auto headlamp
operation. When the headlamp switch is in the PARK or HEAD position,
current flows through CKT 74 (LT BLU) to the underhood
fuse block. The current feeds the following fuses:
• | The TRL PRK fuse (Utility) |
The FR PRK fuse supplies power to the park side of the RH and LH park
and turn signal lamps. The FR PRK fuse supplies power to the LH and
RH front side marker lamps terminal A. During normal operation,
when the park lamps and the turn signals are turned ON, voltage would
be applied to both terminals of the front side marker lamp when the
turn signal lamp flashes ON. When this action occurs, the side marker
lamp turns OFF. When the turn signal lamp turns OFF, the side marker
lamp will illuminate again. This does not occur on the export due
to the marker lamps are directly grounded. The LR PRK fuse feeds
CKT 2509 (BRN) which supplies voltage to the LH rear park
and turn signal lamps (tail and stoplamp on export). On the pickup,
CKT 2509 (BRN) also supplies voltage to the LH rear license plate
lamps and the LH rear side marker lamps. On the utility, the LH rear
park and turn signal lamps (tail and stoplamp on export) are grounded
to G450 via CKT 1350 (BLK). On the pickup, the LH rear park
and turn signal lamp, LH rear license plate lamps and the LH rear
side marker lamps are grounded to G475 via CKT 1750 (BLK).
The RR PRK fuse feeds CKT 2609 (BRN/WHT) which supplies voltage
to the RH rear park and turn signal lamps (tail and stoplamp on export).
On the pickup, CKT 2609 (BRN/WHT) also supplies voltage to
the RH rear license plate lamps and the RH rear side marker lamps.
On the utility, the RH rear park and turn signal lamps (tail and
stoplamp on export) are grounded to G450 via CKT 1350 (BLK).
On the pickup, the RH rear park and turn signal lamp, RH rear license
plate lamps and the RH rear side marker lamps are grounded to G422
via CKT 2250 (BLK). The TRL PRK fuse (utility only) supplies
power to CKT 2109 (BRN) which feeds the LH and RH (and center
on export) rear license plate lamps. The lamps are grounded to G402
via CKT 1650 (BLK). When the park lamp switch is in the PARK
position, the daytime running lights are ON when the ambient light
sensor senses daylight, and the headlights will be ON when the ambient
light sensor senses darkness.
Stoplamps
Pickup
During stoplamp operation, power is supplied from the STOP LP fuse
in the underhood fuse block through CKT 1540 (ORN) to the TCC/stop
lamp switch. When the brake is depressed, the contacts of the TCC/stop
lamp switch close, routing power to CKT 17 (WHT). CKT 17
supplies power to the VECHMSL fuse and the high mount stoplamp relay
coil. Current flows from the VECHMSL fuse through CKT 1320
(LT BLU) to the dome and high mount stoplamp. The ground is
provided by G202 through CKT 1850 (BLK). The high mount stop
lamp relay coil is grounded through CKT 350 (BLK) to G102,
which energizes the relay. When the high mount stoplamp relay is
energized, current flows through CKT 895 (YEL) to the turn signal
switch. Current then flows to CKT 1418 (YEL/BLK) and CKT 1419
(DK GRN/WHT). CKT 1418 (YEL/BLK) supplies power to
the LT TRN (rear) fuse, which feeds the LH rear park and turn
signal lamp terminal A, through CKT 618 (YEL). Ground
is provided by CKT 1750 (BLK) to G475. CKT 1419 (GRN/WHT)
supplies power to the RT TRN (rear) fuse, which feeds the
RH rear park and turn signal lamp terminal A, through CKT 619
(DK GRN). Ground is provided by CKT 2250 (BLK) to G422.
When the left or right turn signal is turned ON, the appropriate
turn signal will flash. The opposite side will remain ON in order to serve
as a stoplamp when the brakes are applied.
Utility
During stoplamp operation, power is supplied from the STOP LP fuse
in the underhood fuse block through CKT 1540 (ORN) to the TCC/stop
lamp switch. When the brake is depressed, the contacts of the TCC/stop
lamp switch close, routing power to CKT 17 (WHT). CKT 17
supplies power to both the VECHMSL fuse and the stop switch contact
of the hazard switch. From the VECHMSL fuse, current flows through
CKT 1320 (LT BLU) to the high mount stoplamp and high
mount stoplamp resistor. The ground is provided by G450 through CKT 1350
(BLK). From the stop switch contacts of the hazard switch, current
flows through the turn signal switch to CKT 1418 (YEL/BLK)
and CKT 1419 (DK GRN/WHT). CKT 1418 (YEL/BLK)
supplies power to the LT TRN (rear) fuse (which feeds the LH rear
park and turn signal lamp terminal A) through CKT 618
(YEL). Ground is provided by CKT 1350 (BLK) to G450. CKT 1419
(GRN/WHT) supplies power to the RT TRN (rear) fuse (which
feeds the RH rear park and turn signal lamp terminal A) through
CKT 619 (DK GRN). Ground is provided by CKT 1350
(BLK) to G450. When the left or right turn signal is turned ON, the
appropriate turn signal will flash. The opposite side will remain
ON in order to serve as a stoplamp when the brakes are applied.
Export
The power supply for the stoplamps is the same as the utility except
that the stoplamp bulbs are fed directly by the same CKT 1320
(LT BLU) as the high mount stoplamp. There is no connection between
the turn signal switch and the stoplamps which operate independently
of the turn signals.