I purchased a 1991 Silverado for my son and the windows worked fine for a month and then they started to stop and go at times. I replaced the switches and checked the relay and all were fine. I then took the panel apart and it looks like the previous owner made speaker holes in them and damaged some of the wires in the process. I checked to see if the switches were getting any juice and the lock switch is and the window switches would go on and then dim to off. I touched the relay and it was very hot. So I'm looking at replacing the door wiring harness to see if that is a fix, problem is that the harness is an obsolete part at the stealers and at any aftermarket supplier :O( Any help would be appreciated :O)