I am in the middle upgrading the stereo in my 04 LE KC big tow, after I put everything back together I notice the passenger side power mirror will not adjust left to right, it wil go up and down but not left to right.
I did run some wires thru the boots (both drivers side door, and pass side door) with a coathanger and could have snagged a wire but I dont know where or what to check.
--edit
I got into the boot and found the purple/red stripe wire was busted in two

I jumped it with a new wire and everything works
Lesson learned: Make sure you chop off the sharp end of the coathanger before you run it thru.