alfredripple

i have a 78 and the window motor is bad but the problem is that the window is down and I need it up to change the motor or can I change it with the window down

DUB

Sometimes using a battery charger on high amps and directly applying 12 volt power to the motor itself on one of the terminals and see if you can get it to move...and tapping on the motor can often times shock it and make it move so you can get the motor out and replaced. The ground clamp of the charger needs to go on the door somewhere...where you know you are getting a good ground. And yes...sometimes the motor is shot.

Hopefully that works...because it is a real fun job if the window is down and will not go up.

DUB

BKbroiler

Try hitting the motor with a hammer with the ignition on and holding the switch in the up position. It worked for me.

Oldguard 7

jumper wire from battery to window motor.

ranger9812

Did you ever figure out an easy way to get that old motor out? I'm in the same spot and looking for an answer other than to un fasten the whole regulator set up and start from scratch.

The advise given above won't help me. My motor is shorted out, and as soon as I hit the switch, the fuse blows. Raising the window electrically is not an option.

DUB

You did try to straight wire to teh motor and forget about teh switch....correct????

If you do and it is shorted out...which I know can occur when I use my battery charger to give it a good amount of amps to get it moving.

I am sure that you know that the motor is held to the regulator by 3 bolts with 7/16" heads on them. I have heated and bent wrenches to get to these 3 bolts and them get the motor loose enough to get the teeth to dis-engage from the regulator and pull up on the glass and then get the motor out.

THIS is NO picnic.

DUB

0Willcox Corvette

This is a paper I did on the 70-71 cars.. but it's pretty much the same for your car.




Since 1979 to 1982 cars didn't use the relay.. here is the schematic for your car.

So for you before I tore anything apart.. I’d do as stated above.. Turn the key on and while watching the amp gauge attempt to roll up or down the window. If the amp gauge deflects then you have power to the switches and the motor. More than likely you have a motor ground issue or something is binding the motor or regulator.

If you have deflection, remove the door panel from the car and the motor cover. Pull the motor plug and test for power at the motor on both wires. Then run a temporary jumper ground to the motor and try again. If this fails the motor is either defective or bound up.


I hope this helps you.

ranger9812

Appreciate the responses. I had already determined that I'm getting power to the motor. I have almost no resistance between the terminals and ground; so the motor is good & shot. I tried the charger & hammer method, but it's not going anywhere. Looks I'll be spending some quality time trying to figure out how to get on those bolts...

DUB

If you motor is shot..as you put it...you cloud go in and remove the black square metal armature housing from the head that is attached to the regulator. Once you get it off...you can either turn the armature manually or remove it and raise the window....because once the armature is out.....there will be nothing keeping the window from moving.

DUB

Maxx76

Hi,
I have some troubles as well.
The power windows seem to fail both at the same time, and it seems that high voltage is the only way to have them moving ( ie. right after start, when the alternator is delivering high current to the battery.)

Could this be the relay ?

BLUDICE

I have issues too - seems like the motor lacks enough power to raise and lower the window, or the window is hanging up in the tracks maybe.
I know I need to remove the door panel to investigate but want as much info before tearing it apart.

Maxx76

What year is your car ?

Before 76-77, the power windows use a Relay. After that, the current goes trough the windows switches.
Do you have the widows failing at the same time ?

BLUDICE

It's a '78 - window falling? Sort of. At times I can pull it up or push it down a couple inches - is this normal?

Maxx76

I think the 1978 is wired direct from the switch to the motor.

Can you test the motor with 12v direct current from the battery with a wire ?

scabooshman

Had this same exact problem on my 78 last week. You just have to send power to the motor until it un-jams. Have someone pull the window up while you put power to it. Once the window is up, you can pull the motor out.

nashville68bird

So how did you get the window up?