W124 electric window problem

[John Turner]

I would be grateful for any help: The car is a 1989 W124 250 TD. The probelm: The left (passenger) front window and right rear window are failing to operate. The front left motor was very strong, although I accept that the rear right window motor has been weak and occasionally intermittent for a year or so. I have checked the 25A fuse at position G , which protects the circuit for this diagonally opposite set of windows (the others being Fuse H), and sprayed with electrical contact cleaner. I suspect no power is getting to the windows since I hear no clicking of the motors when the switches are depressed. Since 2 switches involved, seems unlikley to be a double switch failure. Is a relay in the circuit? I welcome any solutions.
Thanks
John

 

[MW]

It could be a poor contact in a window lifting switch. These are quite easy to get to. The easiest option is to swop a suspect switch, with a known good switch. If it works, that's the problem. Then you can take the switch to bits and clean it, especially the contacts. If nothing changes, at least you have eliminated this avenue.

 

[television]

What MW say is the way to go, or if you have a voltmeter you can check what goes in and what comes out of the switch.
Switch contacts are an issue.

malcolm

 

[John Turner]

Thanks,
Will give that a go. I got the near front one working today after hearing some 'clicks' from the motor, but even after stripping the interior panel off the rear right door, I have failed to get this rear one to move. Wires look fine even through door to bodywork area, but there is no life from the motor. I will have a go at the switches tomorrow and report back!
Thanks
John

 

[turnipsock]

You can check the voltage at the motor contacts. Even if the motor is faulty, the voltage should change when you push the switch.

 

[John Turner]

Thanks. The voltage changes when I push the switch. Looks as though I have a dead motor. How easy is changing the motor? Does it come attached to the window regulator? Thanks for any advice.
Regards
John

 

[tom7035]

Try giving the motor a couple of light clouts with a hammer with the switch 'on', might be sticking brushes or something.
It is bolted to the regulator quadrant which has to be removed to change the motor.

 

[John Turner]

Thanks,
I did try giving it a tap, but not while pressing the switch on! Will have another go.
John

 

[turnipsock]

The motor is quite easy to change. There is another thread about this kicking about at the moment.

It's only three bolts that hold it on.

The motors sometimes work and sometimes don't when they are on the way out. Giving it a clout will get it moving at this stage,