69 automatic window problem.

[pooya76]

Hello, I got a 69 280 se. when I first bought it the driver side window had problems goin up and down, but after messing with it a bit it started working. now its stock for good. I took out the controls and cleaned them out. still didnt work. i know its not the buttons. whats the best way to take the actuator out and trouble shoot? thank you

[ARNOLDLewis]

By all means test the p/window motor using a battery. Check the switch using an ohm meter. It should have continuity with the switch held up and down. I am willing to bet though that your problem lies in the wiring were it bends between the car door and the body.

[pooya76]

if the wiring is not the problem how do i take the window and the motor out?

[mercmad6.3]

With the glass up,you undo the three 10mm nuts on the door that hold the motor is place,undo the wires for the motor from the screw terminal block. Don't lose the screws because they are very hard to find. wriggle the motor so the glass drops slightly. Reach up in the door until you can feel the bottom of the glass. there is an arm that connects the motor nit to the glass,on the glass end is a clip which is on the inside of the mechanism. you have to lift this clip up to free the arm from the motors arm. Once it is free,remove the motor and arm as a unit. there are two types of motor unit,a three wire unit and a two wire unit. you can still buy the two wire units new from mercedes but the three wire unit is obsolete and to fit a two wire motor you need to fit a couple of relays to actuate the motor.

[Pooka]

On most cars there are two wires running to the electric window motor and both are positive. One tells the motor to go up and one tells the motor to go down. The motor is grounded through the body of the car.

On Mercedes of this era the motor direction is determined by the poliarity of the wires. That is: when the the window is to go up one wire is (+) and the other is (-). When the window is to go down the poliarity reverses and the motor turns the other way.

You can also dimantel these motors, clean them, and then re-grease them and put them back togetther. This is not hard but it is time consuming.

Before removing the window regulator assembly test the voltage to the motor and see if it is getting there. Put the (+) wire of your volt meter to one of the wires running to the motor and the (-) wire of the meter to an unpainted part of the car (like, in this case, a screw holding the door sill on) and move the window switch. After this you will know which way to work towards your problem.

Pooka

[mercmad6.3]

Pooka,just be aware that his car is a 1969 and may have the three wire motors.And he should check his fuses and the window power relay.
In most cases it's never the motor that fails but the winder mechanism bending because the running strip for the glass has metal inserts ,which rust. As they rust,the strip becomes tighter and grabs the glass. Eventually the windows stop working because this tightness has caused the frame to bend. Often the gears strip( especially on the 3 wire motor units which have steel frames) .It's pointless attempting to fix the winder frames if they are the alloy version. It's better just to buy new ones and fit your existing motors to them.

[noel.brownell]

This is very interesting and useful to read. Thanks for all the great info. I have a 72 280 SE and my passanger window does not go up all the way. The motor is still working but it seems striped out when it is almost completly rolled up it stops moving but makes a bad noise. Any suggestions on that one? Also, my moon roof does not open but I can hear the motor working, I found the motor and mechanical gear in the trunk and messed with the nut but am afraid to mess to much as I may make it worse.

[JeffreyNMemphis]

Noel,

Sounds like your regulator is bad. It is common for the aluminum plate of the regulator to bend and then the teeth gear get chewed up because of the mis-alignment with the motor gear. I just changed out my regulator on the driver's door. Not a difficult job. You can buy the regulator separately and use your good motor.

[pooya76]

thank you all for all your help.