Installing Trailer Wiring Harness without the Z82 Option - keywords accessory brake bulb connector electrical hazard lamp light signal wire

This PI has been revised to add the 2007 model year. Please discard PIT3815.

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

The full size G/H vans without RPO Z82 use a turn signal/hazard flasher module to control the turn signals and stop lights. This module handles the electrical load from the vans turn signals and stop lights. Due to the electrical load being handled by the module, adding additional lights to the system may cause premature failure of the turn signal/hazard flasher module.

On vans equipped with the trailer towing package RPO Z82, the additional electrical load from the trailer's turn signals and stop lights are handled by relays and not the turn signal/hazard flasher module see eSI Document ID 848202 for 2003-2006 or Document ID 1754401 for the 2007 wiring diagram.

If an owner is trying to wire in a trailer wiring harness on a van not equipped with Z82, please advise they cannot connect a trailer with more than 1 stop/turn bulb per side. If a trailer with more than 1 stop/turn bulb per side is connected, it may cause premature failure of the turn signal/hazard flasher module.

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.