GMC 2007 Savana - Manual (Page 282)

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
includes a seven-wire harness assembly at
the rear of the vehicle and a four-wire
harness assembly under the left hand side
of the instrument panel. The seven-wire
harness assembly is taped together and
located in a frame pocket at the driver side
rear left corner of the frame.
The seven-wire harness includes 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 and trailer brake controller.
Seven-Wire Harness
• Light Green: Back-up lamps
• Brown: Parking lamps
• Yellow: Left stoplamp and turn signal
• Dark Green: Right stoplamp and turn signal
• Dark Blue: Use for electric trailer brakes
• Red/Black Stripe: Trailer accessory
• White (heavy gage): Ground wire
Four-Wire Harness (Trailer Brake Controller)
• Black: Ground
• Red/White Stripe: Fused Battery
• Dark Blue: Trailer Brake Feed
• Light Blue: Fused Stoplamp/CHMSL
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