Trailer Wiring Harness
Basic Trailer Wiring
The trailer wiring harness, with a seven-pin connector, is located at the rear of the vehicle and is tied to the vehicle's frame. The harness connector can be plugged into a seven-pin universal heavy-duty trailer connector available through your dealer.
The seven-wire harness contains the following trailer circuits:
• Yellow: Left Stop/Turn Signal
• Dark Green: Right Stop/Turn Signal
• Brown: Taillamps
• Black: Ground
• Light Green: Back-up Lamps
• Red/Black: Battery Feed
• Dark Blue: Trailer Brake*
*The fuse for this circuit is installed in the underhood electrical center, but the wires are not connected.
They should be connected by your dealer or a qualified service center.
If the back-up lamp circuit is not functional, contact your dealer.
If a remote (non-vehicle) battery is being charged, press the Tow/Haul mode switch located on the center console near the climate controls.
This will boost the vehicle system voltage and properly charge the battery. If the trailer is too light for Tow/Haul mode, turn on the headlamps (non-HID only) as a second way to boost the vehicle system and charge the battery.
See also:
Interior
The Yukon's dashboard has the same shape as its GM siblings. That's good news
because the domed instrument panel, carlike dashboard and flush-mounted buttons
make for a handsome design.
This SUV ...
Gasoline Specifications (U.S. and Canada Only)
At a minimum, gasoline should meet ASTM specification D 4814 in the United States
or CAN/CGSB&-3.5 or 3.511 in Canada. Some gasolines contain an octane-enhancing
additive called methylcyclopen ...
Power Door Locks
With power door locks, the switches on the front doors can be used to lock and unlock the vehicle.
If available, the switches are on the front doors.
(Unlock): Press to unlock the doors.
(Lock): Pr ...





