power windows 83 240D
 

83 240D
And next on my to do list is,,,,, ta da,,,, power windows. So far what I know is (not much) Two windows are inoperative. The front passenger, and the rear drivers side. no motor sounds that I can hear, and the rear window will not work with either switch. I will be into the doors to fix the vacuum elements, anyway, so i was wondering if there is a slick way to eliminate or point the finger at the offending component? It's a long drive to any parts house or boneyard. What say ye all?
Jon j

Check the fuses first, then check the switches. If you have power at the switches then take the switch apart and clean with brake clean which most likely will fix it, unless the window motors are bad which is unlikely.

Just as you described it if the windows are on oposite sides, is a symptom of a bad Fuse or the tips of the Fuse not making good contact.
Mercedes wired the car so that one Fuse controls one Front Window and the Rear Window but on the opposite side.

When this happend to me a visual check of the Fuse looked good. However, when I pulled the Fuse the tip of the Fues was burned off.

The next most frequent cause is the Window Switch Contacts being burned inside of the switch. There is threads in the DIY section on how to clean the Switches.
DIY Repair Links
http://www.peachparts.com/shopforum/forumdisplay.php?f=82
http://www.peachparts.com/Wikka/DoItYourSelf

Almost certainly the fuse, they made them in an X pattern so that there would always be ventilation. There is always the chance of the motors siezing up in these old cars too. Here is your course of action, and check out the excellent links above:
1. Fuses
2. Switches
3. Motors. Sometimes moisture can leak in and corrode the gears and motor mechanism. A good cleaning and lube with WD-40 or PB will get them working again (did all 4 in my SD this way)
4. wiring in the doors. The wiring in the "accordian" rubber boot in the doors can get stripped and brittle with age. Before hacking it all up, check for continuity from the switch to the motor using a multimeter.

RANT :
I do not understand why MB was not smart enough to put some kind of manual emergency window crank in their cars... they had that feature for the moon roofs....

a fuse?
 

I would have never thought that. After all, two windows worked. A fuse would not even been in my sights. I'll look at it in the morning. Thank guys.
And I was going to order a pair of switches. I think I'll hold off on that now
Jon J

X2

Not the fuse
 

83 240D

I checked the fuse, there is power to both sides. I did remove them and clean the ends and the holder. Also switched the fuses with each other, no change. I noticed in the fuse box lid there is a relay for the windows. Could this be the gremlin, and if so where is the little bugger hiding?
I have not ruled out power supply, because of the noted symptoms.
Jon J

Check for power at the switch.

?????
 

Where do i test on the switch. I have no idea where the hot wire is as I have never had the switches out. also If I have power to the fuses does that mean the relay is OK?

Jon J

No. But the fact that at least one window has power would so indicate.

I'm confused
 

Lets see, I asked , if I had power to the fuse does that mean the relay is ok, and you said No. But the fact that at least one window has power would so indicate. Could you clarify that please sir.

Jon J

Where the devil is it
 

I have been searching the posts trying to find the location for the window lift relay. So far it 's located,
1. In a box on the fender
2. Behind the instrument cluster
3. On the firewall above the brake booster.

There seems to be either one or two.

Is the relay ahead of the fuse or behind the fuse in the circuit?

Does anyone know from PERSONAL experience
where it is.
83 240D

The relay powers all the windows. If the relay was bad, no windows would operate.

Which of the four window-related fuses are you calling "the" fuse? Relay actuation is fused, relay power is fused, and power from the relay to the window switches runs through a pair of fuses.

The single window relay is in front of the instrument cluster. (Also sometimes described as "behind" the instrument cluster.) Not much point in looking for it, though. Power to fuses a and b, combined with two windows that work, rules out the relay as the culprit.