Today I took my truck to a large rv dealer to have the rv plug repaired.....It took a Certified Master Mechanic on rv's 3 hours to straighten out the mess that a non rv place had done. The main cable bundle to the bumper plug had been cut into and splices for the bed plug put in. Plus he found that so many things had been wired in wrong. It cost 300 bucks to get it fixed. I know that the GMC dealer sent the truck to an after market place to have the in bed plug installed. The repair guy told me it looked like who ever did the work had never done rv work......
The new wiring was tested by hooking up a new rv on their lot....Now maybe my brakes will work...