Volvo VNL Service Manual page 41

Group 30 Electrical System—VNL, VNM
Auxiliary Fog and Driving Lights
Fog and Driving Light Operation
Low Beam High Beam
Headlights Headlights
Fog On Off
Lights
Driving Off On
Lights
* With Parking/Marker Lights on.
Optional driving and fog lights are mounted in the front
bumper. Both of these lights are controlled by a single
Auxiliary light switch mounted to the right of the headlight
switch on the dash.
Fog and Driving Light Circuit Description
•
Fog and driving lights are fed battery power through
fuse 30. Fuse 30 feeds relay R8, which is energized
by wire 140–A from the dash illumination rheostat and
grounded by 0R-G. Relay R8 feeds the Auxiliary (fog
and driving) light switch via wire 34–A.
W3001002
•
Parking Flash
/Marker To
•
Lights Pass *
On Off
Off On
•
•
•
When the Auxiliary light switch is turned ON power is
sent through wire 39 to the LED input on the switch
for switch illumination (wire 0J-G provides ground).
Wire 39 goes from the Auxiliary light switch to the
Aux. Lamp Change Over Relay (R10), which is tied
to the low beam headlight circuit. The relay sends
power over wire 35 to the fog lights. Wire 35 splices
into wires 35L and 35R for the left and right lights.
The fog lights are grounded by wire 0M, then splice
with the driving light grounds. The left lights will splice
into 0M-A, and the right into 0M-B, which splices into
0M-C and then a ground stud on the right side cowl
in the engine compartment. The Change Over Relay
is grounded by wire 0R-J.
Driving lights are turned ON by the Aux. Lamp
Change Over Relay (R10), which is powered by the
Auxiliary light switch, wire 39.
When changing from low beams to high beams, the
headlight dimmer switch powers wire 38–33RA-33R
to change from fog to driving lights. Wire 38 energizes
the Change Over relay coil, switching from fog lights
to driving lights on wire 37. The Change Over Relay
is grounded by wire 0R-J.
Design and Function
39