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Cadillac Repair/Power Windows

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Expert: - 4/14/2009


Question
I'm troubleshooting a 1990 cadillac coupe deville power windows. The passenger button will roll window down but not up. The driver side will roll the passenger up sometimes and down anytime. The drivers side will not go up or down at all. The drivers side is a two button switch one for the driver the other for passenger. The passenger is a single switch. What is most likely the problem? Do they have a relay if so where is it located?

Answer
Hello,

I have dealt with Caddy windows and locks for years. Your answer can be "all of the above."

Switches are notorious for going bad as well as broken wires and power window motors.

I am sure you don't appreciate this answer, but I can assist you in diagnoses.

You may find that when the windows go up, they may be slow or not work at all. These motors are not very strong and slowly fail.

The switches are made of a cheap plastic outer case and contacts fail. They also are subject to moisture during rain storms getting in and out of the car.

Door wires in the boot at the pinch point by the hinge are known to break at the driver's side door. Remember, everything runs off the driver's door, your locks, seats, mirrors, the other windows and locks. This makes this boot filled with about 50 wires in which the plastic insulation gets brittle after time and break--very common!

The boot would be the last place to look because you either have to slit it and tape back together or the right way is to remove the driver's trim panel and remove the harness and boot--very big job!

You don't have a circuit breaker problem. All the windows either work or don't.

The first thing you need is a test light or a meter. Remove the driver's window switch. Turn ignition on and check for power going in. Check both door window switches on the driver's door when toggliung each swtich up and down.

If you find you have power on both sides of the switch on the driver's side, you need a regulator motor. New pretty cheap on Ebay, about $50.

Now, you may find power or intermittent power for the pass door window. If you have power all the time up and down, you will probably find one of two things at the pass door. Either a broken wire in the driver's door or a bad pass switch. Check the pass switch for power. If there is power going to the switch and yet will not go up or down, you need a switch.

If you do all of this and still need help contact6 me a robo14@aol.com, but try to isolate first.

You can find new switches oin Ebay as well.

Good luck!

Rob  

Cadillac Repair

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Rob Painter

Expertise

Alarm system questions cannot be answered on this forum. These systems are not what I can answer. Without being physically at the vehicle and not knowing what kind of electrical service has been done on the vehicle, there is no possible way to give an accurate answer over the internet. My expertise is in Ignition/key based anti-theft systems. These issues include GM VATS (resistor chip in key blade) PASSLOCK (MRD)-ignition lock rotation based, no special ignition key and the PKIII Transponder (computer chip in key) systems. These systems are not alarm based and are integral with the starting of the engine. This is why I cannot diagnose alarm problems without physically looking at the vehicle: Alarm systems are a completely different annimal than ignition key/lock based anti-theft system. Many alarm questions come from vehicles 10 years old, and since older, many hands that had been involved over the years.I am an expert in all GM factory (ignition/key based)systems. Alarm system questions pose to many situations beyond my knowledge as to what has been done to the vehicle over the years. Some guy may have actually wired the stereo into the alarm system. Who knows? Over my past 30 years in vehicle wiring repair, I have seen unbelievable wiring disaters done by guys that consider themselves "mechanics." I have seen stereos and alarms intalled using surgical tape. I have seen modules burn up, un-fused circuits, wiring jambed between the doors and even lamp cord used for a starter kill. To answer alarm questions over the internet without examining the vehicle is like asking; What does it take to remove a dent?

Experience

Education/Credentials-ASE certified. 11 years with a GM dealer and 17 years with a repair facility dealing with only the repair of theft recovered vehicles.

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