Operation CHARM: Car repair manuals for everyone.

Trailer Lamps

PRINCIPLES OF OPERATION

The trailer lamps and battery charge are supplied power by various relays that are energized to correspond with the exterior lighting functions of the vehicle. If equipped, the vehicle also supplies circuitry to support the installation of an aftermarket trailer brake control module (installed by the customer). The vehicle circuitry only supplies voltage, ground, voltage from the parking lamps circuit (to support backlighting), stoplamp switch input and a controlling circuit to the trailer tow connector. The trailer electric brakes themselves are controlled by the aftermarket trailer brake control module and not the vehicle itself.