[misterdf]

Originally Posted by RockyMtnRay

Although I've never physically verified it with a test light/voltmeter, I'm confident the center pin on the '03's 7-pin Bargman connector is indeed the backup lights...when I put my '03 (with the factory tow package) in reverse, the backup lights on my trailer do indeed illuminate. All the other pins on my '03s connector (trailer brakes, turn signals, clearance, 12 V power) were also as per the standard Bargman layout so the center pin has to be as well.

But if you want to be really, really sure, get a test light and a bargman pin layout like this one, and verify that your test light illuminates when you put the truck in reverse with the key on...and doesn't illuminate when it's in any other gear.

Ray
Towing Moderator

Thanks, Ray. I'll grab a test light and check it out. Appreciate the quick response.