slow power window question

[ken garchow]

my 1990 sl has a slow dirvers window, i lubed every thing and replaced the regulator and it is still slow.

i was told by the dealer that if it goes up and down that it is not the motor and that the 129's are known for bad regulators. so that is where i started

also there is a pretty loud squeak as the window goes up and down, but not when move window up and down by hand w/regulator out (and it moves peretty easy too)

motor moves the regulator out of the cau up or down in 6 seconds whichis the same a the passenger side, but in the car you have to pull the window to get it up

should i buy a new motor next?

thanks

[tecqboy]

When I first got my 91 SL, I thought that the windows were moving painfully slow also. When I got the door panels off, I found that the grease on the regulator guides and rollers had turned to a hardened sludge and paste. I cleaned all the moving parts with solvent and relubed everything with lithium grease. The windows run faster now, but still not as fast as on most cars. But if your window runs OK out of the door, I'd look for something possibly binding in the window guides. I think 4 to 5 seconds on these older 129's is about the best the windows will do. You could measure the current draw of the motor if you have an amp meter. It should not exceed about 8 amps going up or at stall ( end of travel ). The circuit is fused for 8 amps. Power is sourced thru a relay in the soft top controller.

[ken garchow]

tend to either work or not work

also thanks for the lube tips did that when changed the regulator,didnt hepl

still slower than the passenger window, and have to give a pull @ times

[LeaUK]

Ken

Had the exact same problem with my drivers window when I purchased. Cleaned and re-lubed regulator completely but didn't fix the issue either.

I bought a new motor and regulator (supplied with motor from memory) which cured it - strange but true.

Now both windows operate almost at the same speed - the new motor and regulator a fraction faster.

I suspect the magnets within the motors may demagnetise over time/temperature, magnetic material certainly demagnetise at the 'curie' point but this is normally a temperature much greater than would be seen in the door - but maybe a partial explanation?!

In my case iI can say it was definatly not the regulator and it was the motor so something is a little strange I agree.

Lea

[Carlos Serrano]

I apologize if it seems like I'm trying to hijack this thread but it brought some issues I have with mine. My right window is slower than the left one by about a second even though I lower the left 5 to 1 to the right, the left window have the tendency of pulling the outside scrapper inside the door when is going down and almost completly stop from the drag I found myself having to wax the outside of the glass at least once a week to prevent this from destroying my scrapper or burning the motor, it only happens in the mornings before the heat of the day. Anybody experience this problem besides myself ?

[Strife]

My 107's driver's side (LH, in my case) is also slower. The way that I use the car, both get absolutely equal usage, but I can't say what the previous owners did.

[stats007]

Originally Posted by tecqboy

When I first got my 91 SL, I thought that the windows were moving painfully slow also. When I got the door panels off, I found that the grease on the regulator guides and rollers had turned to a hardened sludge and paste. I cleaned all the moving parts with solvent and relubed everything with lithium grease. The windows run faster now, but still not as fast as on most cars. But if your window runs OK out of the door, I'd look for something possibly binding in the window guides. I think 4 to 5 seconds on these older 129's is about the best the windows will do. You could measure the current draw of the motor if you have an amp meter. It should not exceed about 8 amps going up or at stall ( end of travel ). The circuit is fused for 8 amps. Power is sourced thru a relay in the soft top controller.

If it's pre '94 the circuit is 16A. Two fuses (left/right) are in the trunk fuse box.

[Tomit1]

When the carbon brushes of the window motor wear out the window becomes slower and slower. Replacing these brushes will help, they can be home-made from some other electric motor and just shaping them to fit.

[speace]

My experience was much the same as Lea's.
Replacing the motor restored the speed of my slow-moving driver's window.