Dodge RAM TRUCK 1500 1995 Service Manual page 686

J R
8W-50 FRONT LIGHTING
8W - 50 - 1
FRONT LIGHTING
HEADLAMPS
The headlamp switch has three positions: OFF, PARK
(parking lamps) and ON. The headlamp switch powers
the headlamps through the multi-function switch.
FLASH-TO-PASS (OPTICAL HORN)
Circuit A3 from fuse 6, a 40 amp, in the Power Dis­
tribution Center (PDC) supplies battery voltage to
the headlamp switch. The headlamp switch has an
internal circuit breaker that connects circuit A3 to
circuit L20.
In the OFF or PARK position, the headlamp switch
feeds circuit L20 which connects to the multi-function
switch. Circuit L20 powers the high-beam on -circuit L3
when the operator flashes the headlamps with the turn
signal stalk of the multi-function switch.
HEADLAMP SWITCH IN ON POSITION
When the headlamp switch is in the ON position,
circuit A3 connects to circuit L2. Circuit L2 connects
to the multi-function switch and feeds the low beams
on circuit L4.
When the operator selects high beam operation, cir­
cuit L2 connects to circuit L3.
HEADLAMP GROUND
Although circuit Zl provides ground for both the
right and left headlamps, it has different termination
points for each.
PARKING LAMPS
The headlamp switch has three positions: OFF, PARK
(parking lamps) and ON, plus a dimmer switch. When
the headlamp switch is in the PARK or ON position, the
switch connects circuit F33 to circuit L7. From the
headlamp switch, circuit L7 branches to power the front
parking lamps and rear tail lamps, roof clearance and
identification lamps, fender lamps and rear license plate
lamps. Circuit Zl provides a ground for the parking
lamps. Ground for the roof clearance and identification
lamps is supplied on circuit Z4.
FOG LAMPS
The fog lamps are controlled by the fog lamp
switch and fog lamp relays. The fog lamps operate
only when the headlamp switch is in the PARK or
ON position, and the operator has selected low-beam
operation. When the headlamps are in high-beam op­
eration, the fog lamps will not operate.
Circuit L38 supplies power to the contact side of
fog lamp #1 relay. Circuit L7 supplies power to the
coil side of fog lamp #1 relay. Circuit L72 connects to
the coil side of the relay and to ground on circuit Z3
through the fog lamp switch.
When the fog lamp switch CLOSES, the fog lamp
relay #1 contacts CLOSE connecting circuits L38 and
L139. Circuit L139 powers the contact side of the fog
lamp #2 relay. When the headlamp high beams are
OFF, the fog lamp #2 relay is not energized and volt­
age flows through the normally CLOSED contacts to
circuit L39.
Circuit L39 supplies voltage to the fog lamps and
the illumination lamp in the fog lamp switch. Circuit
Zl provides ground for the fog lamps.
If the high beam lamps are on, circuit G34 ener­
gizes the fog lamp #2 relay. When the relay ener­
gizes, the contacts OPEN and power is not supplied
to the fog lamps. Circuit Z3 provides ground for the
coil side of the fog lamp #2 relay.
DAYTIME RUNNING LAMP (DRL) MODULE
On vehicles built for sale in Canada, the low-beam
headlamps operate when the ignition switch is in the
RUN position and the park brake switch is OPEN.
Circuit LIO from fuse 15 in the fuse block supplies
voltage to the DRL module. Circuit A3 from the PDC
connects to DRL module.
The DRL module receives information on park
brake switch position on circuit Gil.
Circuit L4 powers the low beams of the headlamps.
When the headlamp switch is OFF, the DRL module
powers the low beams on circuit L4. When the head­
lamps are ON, the multi-function switch powers the
low beams on circuit L4.
Circuit L3 feeds the high beams of the headlamps.
When the operator flashes the headlamps with the
stalk of the multi-function switch, the DRL senses
voltage on circuit L3 and stops supplying power to
the low beams on circuit L4. Circuit Zl provides
ground for the DRL module.
DIAGRAM INDEX
Component
_ _ j p g p
Daytime Running Lamps 8W-50-9
Fog Lamp Relays . 8W-50-3
Fog Lamp Switch . .8W-50-7
Fog Lamps 8W-50-7
Fuse Block Fuses .8W-50-4, 8
Headlamp Switch . . . 8W-50-4
Headlamps .8W-50-3, 6
Ignition Switch 8W-50-8
Park/Turn Signal Lamps . 8W-50-5
PDC Fuses 8W-50-3, 4, 6, 8
Roof Clearance Lamps .8W-50-10
Roof Identification Lamps .8W-50-10