Cab Electrical Systems; R/V Cab Harness Routings - GMC G Service Manual

8A-10 CAB ELECTRICAL

CAB ELECTRICAL SYSTEMS

R/V CAB HARNESS ROUTINGS

There are several wiring harnesses routed throughout
the cab which provide continuity between the electrical
components. These harnesses consist of: the instrument
panel harness, the power door locks and power window
harness, the radio harness, the heater harnesses, the air
conditioning harnesses and the interior lighting harnesses.
INSTRUMENT PANEL HARNESS (Figure 15)
This harness is located along the upper back edge of the
instrument panel. It starts from the fuse panel which is
located at the left side of the dash panel, and goes up to the
left side of the instrument panel and across the instrument
panel to the right side of the cab.
As the instrument panel harness is routed across the
instrument panel, various circuits branch off to the
switches, indicators, and the instrument panel. The harness
is held in place with bendable clips.
Other harnesses are carried in the same supports as the
instrument panel harness. These consist of the power door
locks, power window, radio, heater and air conditioning
harnesses.
POWER DOOR LO CKS AND POWER WINDOWS
HARNESS (Figures 16 and 17)
This harness starts at the fuse block and routes to the
left and right along the instrument panel. At the middle of
the instrument panel, the harness branches off to the relay
assembly. The relay assembly is located on the inside of
the dash panel, just above the steering column. The har­
ness then goes to a set of connectors on the inner wheel
housing. From the connectors the harness passes through
a grommet in the front door opening trim panel and then
through a flexible coupling to the door. Inside the door the
harness branches off to the control switches, the door lock
motors, and the power window motors. The harness con­
nectors are fastened to the control switches with retaining
nuts.
REAR DOOR POWER LOCK HARNESS (Figure 18)
The rear doors power lock harness starts at a connector
in the fuse block. The harness is routed along the instru­
ment panel harness, with a branch going to the power door
lock switch assembly in the instrument panel. The harness
then drops down the right front door hinge frame and routes
back along the right door sill to the right front door latch
frame. The harness then travels up the right front door latch
frame to its midpoint where a connector is located. The
harness then goes to the roof halo panel and back to the
rear door frame.
At the rear door frame, the harness is connected to a
contact assembly on the right rear door frame. This contact
assembly is aligned with a contact assembly mounted on
the right rear door. From the contact assembly on the door,
the harness then goes to the lock motor.
CARGO LAMP HARNESS (Figure 19)
The harness starts from the instrument panel harness
and routes under the left front door sill. The harness then
goes up the left front door latch frame, through a connector,
and into a control switch.
From the control switch, the harness goes down the
frame, back along the rear door sill and then up the rear
door latch frame. From the top of the frame the harness
goes to the cargo lamp.