Electric Windows

Generally they're riveted together and not repairable. What's the symptom?

That is commonly caused by gummed up front and rear rubber channels. The clue is it goes down better. Use a silicone spray to wash down the channels. It sprays on like water, then evaporates and leaves a slippery film behind. The Chrysler dealer's parts department has this lubricant called "Silicone Spray Lube". I'm sure other dealers have the same thing with their own names on the can. You can find it at the auto parts stores too.

If the lube doesn't help, listen for a grinding sound when the window moves up or down. If you hear that, suspect broken plastic pulleys or frayed cables in the window mechanism.

My experince has been bad thermistors in the motor circuit can cause this slow function. I have removed plastic motor end with brushes and soldered thermistor plates together to acheive good circuit. This however defeats thermistor so overheat can now occur with abuse/fault. Normal use will notice no difference from original.

Are you referring to a glass bulb with a thermal cutout inside? One of my students showed me how his new boss told him to bypass those on their GM trade-in cars. I expressed concern about defeating a safety feature, however, how often do we hold a power window switch long enough for the motor to overheat? I think the safety device causes more problems than they prevent.

While working at a Chrysler dealership, we had a whole rash of weak / sluggish rear vent window motors. The more you worked them back and forth, the slower they ran until they just gave up. Since they were all still under warranty, we never got to open one up and do an autopsy. I wonder if they had a similar cutout that developed burned contacts.

If this cutout is the problem, would the window still go down normally?

No, it's 2 flat plates of brass separated by a thermal material. But the symptoms are as you stated. And yes the window goes down easier than up, but both fade to nil with repeated use without intermission. Hey it's a quick and expenseless fix in this economy. And yah, I think a lot of the companies use similar designs.

That's something different than I envisioned. My student showed me a glass bulb with a bimetallic strip and a contact on it. This was in the right rear door of a Blazer. Window worked fine when he bypassed that unit.

I had some of those thermal cutouts in the glass tubes many years ago. I soldered some to those blown "new-style" fuses that looked like two spade terminals side by side, molded into a plastic handle in my new 1980 Volare! That was the first car I had that didn't use glass cylinder fuses. I kept popping fuses after adding a trailer hitch and wiring. Turns out, the contacts would overheat after about 50 miles and the running and tail lights would flicker on and off. Here again my "fix" caused more trouble than it prevented. Had I been as smart back then as I claim to be now, I would have just popped in a circuit breaker that fits the same slots.

Anyhow, thanks for the description. Next time I visit a salvage yard I might look for one of those to take apart and peed inside.

The design i'm referring to I found in the riveted motor/gear assmbly units with plastic brush holders that are removable by bending a couple tabs up. I have not done very many so I have not seen the other style thermistors. I have also run across this problem in some heater resistor unit designs. They sometimes also have a replaceable/shortable thermistor.