[crazyred]

If you have a trailer wiring hook up I would start with that … then work your way underneath the truck looking and feeling every inch of wire run back to the cab. reason for is because there is a lot of crap could have been kicked up pinch or damaged the insulation and also trailer wiring is known to do crazy things … plus you hate yourself if you tear apart the column to find out that it was something as easy as replacing a foot or two of wire at the back end of the truck. but thats just my two cents