Power window electrical problem

[cardudeusa]

I have an 87 GT that I'm trying to sell and now all the sudden the passenger side window is acting up. Here’s the problem, window goes up no problem but it won't go down using the switch.

I've done a little trouble shooting and have discovered when I press the switch up the red wire on the motor is grounded and the yellow wire is positive, but when I press down on the switch both the red and the yellow are positive, but if I touch the yellow wire to a ground the window goes down perfectly.

Anyone ever run into this problem??? I'd like to get it fixed so I can get more for the car.

 

[cardudeusa]

TTT

 

[rd]

If you are in a hurry to fix it and get on with life, I would simply change the window motor. My F150 did exactly this, and the new motor fixed it. After removal, the old motor ran up and down nicely when connected to power, but the new one worked the window just fine.

Otherwise, I would troubleshoot the switches and wiring and then replace the motor. The switches are not as simple as they appear. In the center position both leads of the motor are grounded. When you move the switch, one lead stays grounded, and the other moves to connect to power, moving the window motor. For the other direction, same thing, other direction.

A wiring diagram is essential for troubleshooting them. The last 3 of mine have been fixed with motor replacement.

 

[Blown88GT]

Bad switch, replace it, not too expensive.

 

[bill302]

i had this happen to me i removed switch and took it apart and cleaned contacs within switch then it worked great replace switch or attempt to clean contacs.click on lihk heres one for $17.50 w/shipping

http://cgi.ebay.com/ebaymotors/87-9...50459QQitemZ8031894927QQrdZ1QQsspagenameZWDVW

 

[jrichker]

See the following website for some help from Tmoss (diagram designer) & Stang&2Birds (website host) for help on 88-95 wiring
http://www.veryuseful.com/mustang/tech/engine

Diagram courtesy of Tmoss & Stang&2birds

 

[cardudeusa]

Thanks for the diagram jrichker.

As far as the other 3 posts go I tried a window switch from my 90 GT which has windows that work perfect and still had the same problem on the 87. I also put a window motor in from an 88 junk car I have and still the same problem

 

[Bolt on 5.0]

I would check the master switch on the driver door first, if I remeber right there are 2 seperate switches on the drivers door. There should be power to one side of the switch only when pressing the switch, the other side should be ground and vice versa. Its gonning to be a bad switch but you must find out what one it is.

 

[Bolt on 5.0]

Also check is there constant power to the motor without the switch pressed.

 

[cardudeusa]

I would check the master switch on the driver door first, if I remeber right there are 2 seperate switches on the drivers door. There should be power to one side of the switch only when pressing the switch, the other side should be ground and vice versa. Its gonning to be a bad switch but you must find out what one it is.

I don't think its a switch. I swapped the entire set up driver and passanger side from my working 1990 GT driver and passanger side and it made no diff.

Also I'm pretty sure theres not suposed to be a constant power to the motor, because the switch just reverses the polarity to go up or down.

 

[Bolt on 5.0]

Yeh I was asking that question to see if the switch was sticking, you are correct about the switch polarities. Was not sure if you were familiar with home the system worked. If the switches are not chaging anything I would next grab the wire harness in the door jamb and move it around a bit first drivers side, then passenger side. Do one at a time and check to see if the window starts to work, if so you probably have a chaffed wire in one of the door accordians.

John

 

[cardudeusa]

I would next grab the wire harness in the door jamb and move it around a bit first drivers side, then passenger side. Do one at a time and check to see if the window starts to work, if so you probably have a chaffed wire in one of the door accordians.

John

Good idea, I'll have to check into that.

 

[jrichker]

The window motor in my Stang died yesterday, so I spent this morning digging through the local junkyard for a motor.

I learned a few things along the way.
1.) The actual electric motor part is interchangeable between LH & RH motor/gearbox assemblies.
2.) There are 3 nylon rollers inside the motor gearbox. They are about 1/4" long and 7/16" in diameter. They get chewed into ltttle pieces and may jam the gear so that the motor won't turn. Sometimes the rollers break and the motor runs, but the window may not move, or may move with a jerky motion. I don't know if you can get the rollers from Ford, but I suspect they would be handy to have for spares.

 

[cardudeusa]

The window motor in my Stang died yesterday, so I spent this morning digging through the local junkyard for a motor.

I learned a few things along the way.
1.) The actual electric motor part is interchangeable between LH & RH motor/gearbox assemblies.
2.) There are 3 nylon rollers inside the motor gearbox. They are about 1/4" long and 7/16" in diameter. They get chewed into ltttle pieces and may jam the gear so that the motor won't turn. Sometimes the rollers break and the motor runs, but the window may not move, or may move with a jerky motion. I don't know if you can get the rollers from Ford, but I suspect they would be handy to have for spares.

You can get the little rollers ad Advance Auto, they are in the Help section. I replaced those when I swapped in the new motor.

 

[HISSIN50]

The little roller dealies should be there as a sacrificial limiter to cap upward torque supplied by the motor if something is stuck between the window and door frame (like a kid's hand).

I applaud you guys for replacing them with the OEM part, rather than metal like some folks do.

 

[cardudeusa]

Well Bolt on 5.0 you were right. The yellow wire inside the drivers door accordian was the problem. All fixed now.

Thanks everyone!