Windows will not role down
Thread Starter
Intermediate
Joined: Apr 2019
Posts: 42
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From: Las Vegas, NV
Windows will not role down
What is going on ya'll? I have an 81 U.S. spec 928. She has been sitting in a garage since 95 and I am just getting her going. I can't seem to get the windows to role down or up for that matter. I checked the fuse and it seems fine. Could it be the relay? Is there an easy fix for this or am I looking at faulty regulators. Looking for some advice. Thanks in advance. Steve
Team Owner
Joined: May 2004
Posts: 31,179
Likes: 4,172
From: Philly PA
take the door panels off and put 12 v to the window motor.
NOTE if it wont move,then the lift arm assembly needs to be removed.
I have been finding that replacing the brush assembly with a new part fixes most window motor issues
New brush units are available on Ebay 12.00 each, they also come with the power cutout breaker.
Also remove the friction nylon button from the case it pulls straight out, this runs on the arm
sand down the wave washer to remove any rust put DC 111 on the wave washer and reassemble
NOTE if it wont move,then the lift arm assembly needs to be removed.
I have been finding that replacing the brush assembly with a new part fixes most window motor issues
New brush units are available on Ebay 12.00 each, they also come with the power cutout breaker.
Also remove the friction nylon button from the case it pulls straight out, this runs on the arm
sand down the wave washer to remove any rust put DC 111 on the wave washer and reassemble
Burning Brakes
Joined: Aug 2018
Posts: 806
Likes: 61
Does it have a relay? Im not familiar with your car. The motors or the switches could be bad or need cleaning. But since its both if there is a relay why not replace it? Im kind of lazy so that would be my first approach before pulling other things off.
Rennlist Member
Joined: Mar 2003
Posts: 1,195
Likes: 78
From: Washington DC
No relay. You can do a quick check to see if the switches work by turning the car to on (not start) then watching the voltage meter carefully when you push the switch. If you see a little deflection then the motor is stuck. If no deflection the switch might be bad.
On mine the motors were dry with no lubricant, some lithium grease on the bushings and a squirt of penetrating oil into the gear case made everything happy again.
Note 2: When removing the window lift assembly it's a lot easier to remove the motor *first* with the 3 bolts, then take out the lift, clean, and lubricate.
On mine the motors were dry with no lubricant, some lithium grease on the bushings and a squirt of penetrating oil into the gear case made everything happy again.
Note 2: When removing the window lift assembly it's a lot easier to remove the motor *first* with the 3 bolts, then take out the lift, clean, and lubricate.
Burning Brakes
Joined: Aug 2018
Posts: 806
Likes: 61
Thread Starter
Intermediate
Joined: Apr 2019
Posts: 42
Likes: 0
From: Las Vegas, NV
Mrmerlin,
Could you help me out a little more on this one. I did what I thought was correct which was throw 12 v at it but I did not get anything. Is there a certain technique and I should not have to ground it right? It is already grounded I assume. Thanks in advance. Steve
Could you help me out a little more on this one. I did what I thought was correct which was throw 12 v at it but I did not get anything. Is there a certain technique and I should not have to ground it right? It is already grounded I assume. Thanks in advance. Steve
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Team Owner
Joined: May 2004
Posts: 31,179
Likes: 4,172
From: Philly PA
On the cars I have resurrected when either window won't work its easy to hear the if anything is happening in the door when the switch is pushed
Based in your report
I would remove both of the window lift assemblies and take them apart and replace the brush holder and clan and lubricate the lift arm pivot and the nylon button
The lift arm assembly will come free after you remove the 4 bolts that hold it in the door
Note its common for cars that have sat outside to have frozen motor and corroded button washers
my instructions should return the window operation to like new performance
Note it would also be wise to replace the 2 white window guides that run on the center guide tube
adding in a new brush holder is also highly recommended
The 2 pins on the motor are positive and negative reversing the power to these pins will make the motors turn the opposite way
Based in your report
I would remove both of the window lift assemblies and take them apart and replace the brush holder and clan and lubricate the lift arm pivot and the nylon button
The lift arm assembly will come free after you remove the 4 bolts that hold it in the door
Note its common for cars that have sat outside to have frozen motor and corroded button washers
my instructions should return the window operation to like new performance
Note it would also be wise to replace the 2 white window guides that run on the center guide tube
adding in a new brush holder is also highly recommended
The 2 pins on the motor are positive and negative reversing the power to these pins will make the motors turn the opposite way
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Burning Brakes
Joined: Aug 2018
Posts: 806
Likes: 61
Mrmerlin,
Could you help me out a little more on this one. I did what I thought was correct which was throw 12 v at it but I did not get anything. Is there a certain technique and I should not have to ground it right? It is already grounded I assume. Thanks in advance. Steve
Could you help me out a little more on this one. I did what I thought was correct which was throw 12 v at it but I did not get anything. Is there a certain technique and I should not have to ground it right? It is already grounded I assume. Thanks in advance. Steve
Rennlist Member
Joined: Jul 2010
Posts: 1,774
Likes: 406
From: Bowling Green, KY
Both positive and negative have to be connected. Depending on how it is applied, it may be necessary to reverse polarity before throwing in the towel on the motor because your first effort may have actuated the motor to put the glass up.
Go get a couple female spades that will fit the pins of the motor. Crimp them on to some extra 12-14 gauge wire if you have some. Leave the wire at least 10" long. Strip the wire end where you will connect your charger. Hook positive and negative wires. If nothing happens, swap the charger leads.
Go get a couple female spades that will fit the pins of the motor. Crimp them on to some extra 12-14 gauge wire if you have some. Leave the wire at least 10" long. Strip the wire end where you will connect your charger. Hook positive and negative wires. If nothing happens, swap the charger leads.
Rennlist Member
Joined: Jul 2006
Posts: 5,422
Likes: 627
From: Bloomfield, MI
Yep ^^^^, done one of mine last week, I'll add if your interior lights are working, you should see the bulb slightly dim as the switched is pressed (if you are not using LED's 
Also do not overlook a faulty Ignition switch (wiggle the key while pressing the window switch), I've been there and done that too.
Dave K
Also do not overlook a faulty Ignition switch (wiggle the key while pressing the window switch), I've been there and done that too.
Dave K
Thread Starter
Intermediate
Joined: Apr 2019
Posts: 42
Likes: 0
From: Las Vegas, NV
Please forgive me if I am off on this but I ran a wire from the the + post in the engine bay and had another wire grounded. That is what I was using to test the motor. Do I have to use an external small 12 v battery or is what I am doing correct also? Thanks. Steve
Burning Brakes
Joined: Aug 2018
Posts: 806
Likes: 61
If you are dead certain that your battery is sending 12v or more to the jump post then it should work fine (confirm that with a multimeter if you have one). The motor needs to be grounded, preferably with a wire to a known good ground. I havent fooled with a window motor in over 20 years, but if I understand it correctly it doesnt matter which terminal is + or -, swapping the wires around will just make it turn in the opposite direction.
Last edited by Shark2626; Jul 25, 2019 at 05:04 PM.
Thread Starter
Intermediate
Joined: Apr 2019
Posts: 42
Likes: 0
From: Las Vegas, NV
So the motor does work and I was able to get it up and down with connecting a direct power source. Fuse is good so with process of elimination can I assume it is the relay? Thanks y'all. Steve