I have a '97 XL. Whenever I use the brakes, the white back-up lights come on as well as the red brake lights. The truck came factory wired with an adapter for trailer lights. The problem only presented itself after I started towing my boat (this may be coincidence). I have checked underneath for loose connections, chaffing, or broken wires and all seems fine. Any suggestions on how to attack my problem? A Ford tech told me over the phone that I probably have a ground somewhere. Does this sound right?

 

It's not a ground, it's a short. Somewhere a short between the brake light circuit and the backup light circuit has ocurred.

Have you done any wiring changes to the truck to hook up your trailer lights? That's the first place to look.

If not then the factory 7 pin connector is where the short is. Both the brake lights and the backup lights are wired into this connector and whatever you have plugged into it may have bent the pins or otherwise caused these circuits to have contact with each other. Take a very close look and hopefully you will see the damage and can fix it, otherwise you may have to replace the whole connector. Also check for any damage to the wires going into the connector on the back side.

 

Hawkeye-
Thanks for the advice. Before I had a chance to really look over the wiring, I got stuck. The ABS light went on and stayed on, and the tranny locked itself in Park. After a tow to the dealer, the mechanic found that the U-haul installed hitch had crushed the wiring harness going to the rear of the truck, thus shorting a couple of the wires.

U-haul was great about handling the problem, and has agreed to pay for the damages. For once paying the extra money for installation paid off. The total came to $245.

Thanks again.

 

You're welcome. I'm glad you found the problem and even more glad to hear that someone else is picking up the tab for the repair.