I am another of the long list of people who had a problem with power windows on my 2006 F150 Lariat 4 x 4. Sometimes the windows would work, and sometimes for no apparent reason, they would fail to operate at all. No just one window, but all four would go out at once. Then, all of a sudden, everything would start working.

I eliminated the fuse and relay, so I figured the master control switch was bad. I replaced it, and much to my surprise, the same problem continued. After much research, I learned about the wiring problem between the cab and driver's door. It seems the ground wire would sometimes break in the "fold" of the wiring harness. I fulled back the wiring boot and could not believe my luck. A large (#12) black wire was broken in two right in the middle of the fold. Looked like someone took a pair of wire cutters and snipped it.

I cut back the wiring (on the door side) and added (soldered and shrink wrapped) a new piece to it. I then attempted to do the same thing to the connector side of the wire. As I manipulated the wire, the darn thing broke again inside of the connector. Now, I was stuck. I decided to try another approach. I eliminated the connector completely and exited the ground wire through the boot. I then grounded the wire inside of the door well. Everything worked great, and everything is working again. No issues at all.

If anyone is having weird problems with power windows, be sure to check the ground wire INSIDE of the boot. You may get lucky