We had a customer come in with a 2000 Pontiac Bonneville come into our shop because her 4 windows stopped working. She told us that she had the windows rolled down and suddenly all 4 windows wouldn’t roll up anymore. Since all 4 windows stopped working at the same time we knew the problem was electrical. If it was a single window then we could safely assume that it might be a window regulator or motor, but since all 4 stopped working at the same time we knew we had an electrical problem to deal with.
Since it was an electrical problem we tested a door window switches and we could hear the relay inside each door click/actuate when we hot the switches for window up or down. So they were working fine.
Then we checked fuses to make sure that it wasn’t a simple blown fuse. We went one by one until we got to the 30 AMP fuse that gave power to the window motors was extremely hot. It was too hot to pull out by hand so we had to oull it out with pliers. This immediately told us that there was a short circuit in the vehicle causing the fuse to always recieve power making the 30 AMP fuse run hot!
So we now knew the problem was a broken wire or wire insulator somewhere in the car! But where would we find this wire as the wiring harnesses on cars have hundres of wires hidden all over the car. Since it was an older vehicle we checked out a mechanic’s database known as IdentaFix, which lists all common pattern failures.
We found that there was a common issue on this particular car model where some wires that correspond to the window switches get corroded or break under the driver’s seat, which cause all 4 windows to stop operating. So we started by removing the driver’s seat.
With the driver’s seat removed we were able to remove some plastic trims and finally remove the carpet. We found the wires that commonly corrode and cause the 4 windows to stop working. We found some corrosion on the wires.
We replaced the damaged section, soldered, and weatherproofed the new wires. And once that was done we immediately tested the windows and nothing! We didn’t have luck with that common repair!
Now we knew that we would have to try to find the broken wire elsewhere as Identafix didn’t list any other common solutions for all 4 windows not working. We would have to check the wiring for each door and disconnect each door individually until that 30 AMP window fuse would stop getting hot. We would logically start with the driver’s door as that is the most opened and closed door. Between the door and the body of the car there is a main door connector hidden in between. We started with the driver’s door and then checked the 30 AMP fuse again and it stopped overheating! So we now knew there was a broken wire or insulator in that door causing the short circuit.
Upon closer inspection we found the broken wire insulators and proceeded to repair them. We replaced the damaged sections of wires and the problem was resolved. Now all 4 windows worked perfectly as intended! After putting the interior back together we had another happy customer @ Tolima’s Auto Center.
