Burnt power window switches!!

[mvbrian]

So my girlfriend called me last night in a panic. She was driving my 92 e34 and smoke started coming out of the power window switches. She tried to open the sunroof and windows but nothing worked. I checked the fuses and it was fine. I pulled the switches and found the driver side rear switch was just toasted...BAD! What causes this without blowing the fuse. I have ordered and new set of switches but want to know if there is another fuse I need to check. I cant believe that it wouldnt blow some hidden fuse somewhere with that much damage. I was surprised at how easy it was to get the old set switches out. What is the best way to clean the gunk out of them if and when they get dirty.

[joshua43214]

I have never seen actual smoke come from switches. But I have seen them melt down pretty badly, even to the point on melting the connector. Doesn't surpise me that it would smoke. The fuse won't blow unless the wires get short circuited.

I open the switch up, and hose the inside out thouroughly with brake parts cleaner. Scrap any gunk off the contacts and use a points file if needed. then spray every thing down with electrical contact cleaner. A tiny dab of multi lube on the rocker tip, and all done.

[Javier]

350 watts without fusing. This switch is higly sensitive to dirt and liquids spilled over, as the switch has power and ground terminals, it is easy to cause a resistive conducting path, causing severe overheating, and toasting the switch over time.

Javier

[mvbrian]

this thing is far beyond repair. Now that it is disconnected the power sunroof works fine. New parts are on order.