Basic Trailer Wiring

All regular, extended cab and crew cab pickups have a seven-wire trailer towing harness.

For vehicles not equipped with heavy duty trailering, the harness is secured to the vehicle's frame behind the spare tire mount. The harness requires the installation of a trailer connector, which is available through your dealer.

If towing a light-duty trailer with a standard four-way round pin connector, an adapter is available from your dealer.

    See also:

    Potential Issues
    Some OnStar services are disabled after five days. OnStar cannot perform Remote Door Unlock or Stolen Vehicle Assistance after the vehicle has been off continuously for five days. After five days, OnS ...

    How to Detect a Tamper Condition
    If is pressed and the horn sounds, an attempted break-in has occurred while the system was armed. If the alarm has been activated, the THEFT ATTEMPTED message will appear on the DIC. See Key and ...

    Engine Coolant Heater
    The engine coolant heater, if available, can help in cold weather conditions at or below −18°C (0°F) for easier starting and better fuel economy during engine warm-up. Plug in the coolant ...