1988 Pontiac Fiero Power Windows

Tiny
FIEROGUY
  • MEMBER
  • 1988 PONTIAC FIERO
Electrical problem
1988 Pontiac Fiero 6 cyl Two Wheel Drive Manual 85K miles

On my 1988 Fiero GT the power windows work intermittently. That is, I can roll them up and down, sometimes. It seems that when I first get in the car I can operate the windows. But, they run out of "juice" sometimes halfway up. When I first bought the car I rolled the windows up when I got on the freeway. They were slow, but with consistent speed compared to each other. I drove for about two hours and stopped for lunch. When I came out the interior was hot and I wanted to roll the windows down. NO LUCK! I drove home, trying the windows from time to time without success. I came back out the next morning and Voila! The windows worked! The next incident was a mechanic rollled the windows down while it was being smogged. I rolled up the Passenger side first and it started out fine then slowed to a stop half mast. I tried the drivers window with no lluck. Five minutes later I tried the drivers window again and no problem, successful operation of the Passenger side, too. What gives? Is this a heat related regulator problem? It seems as the motors are ok but that something between the switches is bad. But, I haven't a clue on this one. Is there a regulator? Where is it? What else can it be?

Sweating terribly in Fresno
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Monday, July 7th, 2008 AT 7:13 PM

5 Replies

Tiny
MASTERTECHTIM
  • MEMBER
You have smoked window motors and are tripping the internal circuit breakers. Try spraying silicone spray into the window run channels. This will help alot but you will need to replace the motors to make it work perfect. Hope this helps
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Monday, July 7th, 2008 AT 7:18 PM
Tiny
FIEROGUY
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First and foremost, Thanks for a quick answer. It is greatly appreciated. If the motors are toast, why are they still working? It seems that the problem is heat related. For two days after the first incident I described the windows didn't work. But, I checked them in the afternoon. The time they did work was in th a.M. Does this info change anything? Take care and thanks again.
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Monday, July 7th, 2008 AT 7:32 PM
Tiny
MASTERTECHTIM
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Exactly heat related. When its hot out the metal expands causing a drag on the motor armature causing high amp draw thus causing the internal motor circuit breaker to po. To prove my theory just remove the door panel and check for power and ground at the motor when it stops, or try to jump power and ground to the motor and see if it works, I bet it doesnt. This is not uncommon. Happens all the time
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Monday, July 7th, 2008 AT 7:40 PM
Tiny
FIEROGUY
  • MEMBER
Thanks again Tim.

It just seems too convenient for both of them to be out. It could happen, sure. But, just one more stab at it, PLEASE? Is there a relay that could be bad causing the problem, therefore making it unnecessary to have BOTH motors replaced?
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Monday, July 7th, 2008 AT 7:46 PM
Tiny
MASTERTECHTIM
  • MEMBER
Bub im telling you its the motors. Sure anything is possible but with the motors going slow im sure its the motors. To bypass all possibilities of anything else but the motors just put power and ground to the motor and when it stops working and or goes slow, you will be convinced. If it works fine when you put power and ground to it, I will get you the whole diagram of the window circuit and find where every component is. I promise.
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Tuesday, July 8th, 2008 AT 5:43 PM

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