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:

    Services for People with Disabilities
    Advisors provide services to help subscribers with physical disabilities and medical conditions. Push for help with: • Locating a gas station with an attendant to pump gas. • Finding a hotel, ...

    OnStar Overview
    If equipped, this vehicle has a comprehensive, in-vehicle system that can connect to a live Advisor for Emergency, Security, Navigation, Connection, and Diagnostic Services. The OnStar system s ...

    Vehicle Speed Messages
    SPEED LIMITED TO XXX MPH (KM/H) This message displays when your vehicle speed is limited to 128 km/h (80 mph) because the vehicle detects a problem in the speed variable assist steering system. Have ...