Trailer Brakes Locking Up on 2002 Silverado with 6-Way Trailer Connector

Question:

Had a rental company install a 6way, hitch and brake controller the brake controller did not work properly, sent full voltage apparently from brake lights to brakes locking them up as soon as trailer was plugged in. this happened even with the brake controller disconnected. This ws odd because they used their aftermarket factory connector under the dash. Anyhow, we got power to the controller to get the new 30 trailer home. But now we want to purchase a Prodigy controller and adapter from you and get this thing done right. So, I have to ask, what is the VIN cutoff for the harness from 2002 - 2003? The kid at the rental company indicated that the pin that was supposed to be hot under the dash wasnt, so Im wondering if this truck needs the 2003 adapter. Also, does adding a controller require the dealer to tell the computer that the truck now has a controller? My son-in-laws Jeep Grand Cherokee required this for his Prodigy to work correctly. Any advice would help before I sink more money into the Prodigy.

asked by: Rick

Expert Reply:

I suspect that it is not your brake controller that is causing your problem, especially since this is occurring when the controller is disconnected.

There are two accepted methods of wiring a 6-way trailer connector. One method uses the center pin of the connector for the 12-volt accessory circuit, the other uses the center pin for the brake output circuit. If the vehicle is wired using one method, and the trailer is wired the other way, the trailer brakes will immediately receive 12-volts and lock up as soon as the trailer is plugged into the connector.

You can confirm this by using a circuit tester like part # PTW2993 on your 6-way on the truck. Test the center pin and the pin in the 10:00 position to see which pin is hot. Once that is determined, try applying 12-volts to the corresponding pin on the trailer connector using a car battery. If the brakes actuate, then you know the connector on the trailer is wired incorrectly and needs to have the brake output circuit swapped at the connector for the 12-volt accessory circuit.

expert reply by: Mike L