1972 w108 power window trouble shooting?

[TroutMD]

My '72 280se 4.5 rear left passenger power window stopped working today. It went down fine but will not come back up. I dont hear any sounds when pushing the button in either direction. Any suggestions for trouble shooting this? All the other 3 windows work perfectly, same with sunroof. Also, is there way to manually get the window back up without taking out the door panel?

Thanks in advance for any tips.

[cth350]

check the easy thing first, each window has its own fuse. Look at the extra fuse blocks on the firewall.

-CTH

[ejboyd5]

Originally Posted by cth350

check the easy thing first, each window has its own fuse. Look at the extra fuse blocks on the firewall.-CTH

Not exactly. Driver's rear and passenger's front windows share the same fuse as do the driver's front and passenger's rear windows Suggest pulling the switch and reversing the wires to see if you can raise the window. If so, not only will the window be up, but you have limited the problem to the switch.

[tyl604]

Does the 280SE have the famous sliding jaw on the window which breaks and prevents a single window from going up or down? Maybe this is your problem.

[TroutMD]

Originally Posted by ejboyd5

Not exactly. Driver's rear and passenger's front windows share the same fuse as do the driver's front and passenger's rear windows Suggest pulling the switch and reversing the wires to see if you can raise the window. If so, not only will the window be up, but you have limited the problem to the switch.

OK, thanks. How do you pull the switch without damaging it? Thanks again.

[Idle]

You can remove the door card with just a few screws and pulling at the snaps that hold it in.

I think the 1972 had the newer style power window motors with two wires. If you try to remove this without taking out the window regulator it is difficult to get back in correctly.

But if you remove the door card you will have access to everything. You can hit the wires with power directly and get the window up. With the door card off taking the switch out is easy.

The motors with two wires use a reverse polarity system. That is: If you attach 12+ to one wire and ground to the next it will move one way. Reverse the wires and it will move the other. A three wire motor is smaller and easy to remove. One wire is the ground and the other two are up and down. If there is a brown wire it is the ground.

With the switch out you can easily check the plug for power coming to the switch. If it is good then check the output of the other pins with the switch one way and then another.

But the main thing is to get the window up. Jumping 12 volts to the 'up' wires will do this. If the motor turns and the regulator moves but the window does not then you have to check where the regulator arm connects to the bottom of the window. It is just a small clip that holds these together. If it snapped then all you need to do is replace the clip.

You will likely not be able to see this clip because of the way the door is made. But you can easily feel it by sticking your arm in the door and reaching around for the pivot and clip.

Use caution when taking off the vapor barrier plastic. These are slow to come off but nice to have in place. You will need to remove it and replace it to gain access to the interior of the door.