Mechanics

POWER WINDOWS

2002 Pontiac Trans Am

Electrical problem
2002 Pontiac Trans Am V8 Two Wheel Drive Automatic 29500 miles

The drivers side door will start to go up/down for a few seconds and then stop--I can power off the car, wait a minute and it will go up/down again for a few seconds. Window will eventually go all the way up or down after numerous power down delays. Passenger window works fine.

Is this the motor failing--it is getting power but will not advance window all in one motion.
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Daveschmit
August 21, 2010.



Hi daveschmit. Welcome to the forum. This sounds typical of a failing motor. Actually, not the motor itself but the thermal cutout inside the motor. It's an overload protection device that causes way more trouble than it prevents. The contacts become pitted resulting in heat buildup and the device opening the circuit until it cools down and resets.

One local used car dealer solves the problem by disassembling the motors and bypassing the thermal device, but in my opinion, that leaves them open to a lawsuit if it can be proven they did that, and of course, it actually resulted in a problem. Some GM vehicles use way over-engineered window switches with relays built in. If one of those relays would stick and keep power applied, a window motor could overheat. That's why the thermal cutout is needed.

Use a cheap digital voltmeter to measure the voltage between the two wires right at the motor connector. If the voltage is still there when the motor stops working, you'll know the switch and wiring are ok. That just leaves the motor as suspect.

Caradiodoc

Caradiodoc
Aug 21, 2010.
Is the power window motor a D.I.Y. Project--are special tools needed to replace the motor? Any potentially danger issues with window assembly?

Thanks for your initial response.

Tiny
Daveschmit
Aug 21, 2010.
The story I gave you was from a former student who works for that used car dealer. He showed me the thermal cutout on his own vehicle he was fixing. As I recall, the regulator assembly is held in with rivets that must be drilled out, then the motor can be removed, but I don't know if it is held on with more rivets or with screws. It only took my student a few minutes to remove his motor so I'm guessing it is a do-it-yourself project.

Caradiodoc

Caradiodoc
Aug 21, 2010.