Maintenance When Trailer Towing; Trailer Wiring Harness - GMC Jimmy 2004 Owner's Manual

Maintenance When Trailer Towing

Your vehicle will need service more often when you're
pulling a trailer. See the Maintenance Schedule for more
on this. Things that are especially important in trailer
operation are automatic transmission fluid (don't overfill),
engine oil, axle lubricant, belt, cooling system and
brake system. Each of these is covered in this manual,
and the Index will help you find them quickly. If you're
trailering, it's a good idea to review these sections
before you start your trip.
Check periodically to see that all hitch nuts and bolts
are tight.

Trailer Wiring Harness

The light-duty trailer wiring is a six-wire harness
assembly. The optional heavy-duty trailer wiring is an
eight-wire harness assembly. The harnesses are stored
under the vehicle, along the passenger-side frame
crossmember on two-door vehicles or on the driver's
side corner frame rear crossmember on four-door
vehicles. The heavy-duty trailer wiring is fused in the
engine compartment fuse block. See Fuses and
Circuit Breakers on page 5-99. Both harnesses have
no connector and should be wired by a qualified
electrical technician. The technician can use the
following color code chart when connecting the wiring
harness to your trailer.
•
Dark Blue: Use for electric trailer brakes or auxiliary
wiring (eight-wire harness only).
•
Red: Use for battery charging; it connects to the
starter solenoid (eight-wire harness only).
•
Light Green: Back-up lamps.
•
Brown: Taillamps and parking lamps.
•
Yellow: Driver's side stoplamp and turn signal.
•
Dark Green: Passenger's side stoplamp and turn
signal.
•
White: Ground wire.
•
Light Blue: Auxiliary stoplamp.
Securely attach the harness to the trailer, then tape or
strap it to your vehicle's frame rail. Be sure you
leave it loose enough so the wiring doesn't bend or
break, but not so loose that it drags on the ground.
Store the harness in its original place. Wrap the harness
together and tie it neatly so it won't be damaged.
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