GMC 2001 Savana - Manual (Page 234)

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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 optional heavy - duty trailer wiring package is a
seven - wire harness assembly. The four - wire portion of
the harness assembly is stored under the vehicle, along
the driver’s side rear corner of the frame rail. The
three
- wire portion of the harness assembly is stored in a
frame pocket under the rear of the vehicle, on the
driver’s side. The heavy
- duty trailer wiring harness has
a 30 - amp feed wire. Both harnesses come without
connectors 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.
Four - Wire Harness
D Light Green: Back - up lamps
D Brown: Parking lamps
D Yellow: Left stoplamp and turn signal
D Dark Green: Right stoplamp and turn signal
Three
- Wire Harness
D Dark Blue: Use for electric trailer brakes
(seven - wire harness only)
D Orange: Trailer accessory (seven - wire harness only)
D White (heavy gage): Ground wire
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.