Faulty dimmer switch

[cmac2012]

My other post was absurdly long.

More briefly, the right headlight quit working, I put in a new bulb, it did not improve matters, but then had a suggestion to try the high beam, sure enough, the old bulb, and the new bulb still have a working high beam but no low beam. The left side is still working high and low. The dimmer switch is in trouble. It won't hold the high beam - sometimes when I activate it all the headlight function goes out briefly. Only works while when I'm pulling in and keeping the pressure on it.

I had a similar problem with my Chevy van the dimmer switch went south and I lost both high and low beam.

This is an expensive part. Pelican has it for just under $200 new. I'm going to hit the boneyard. This car has nearly 400 K on the body, a lot less on the engine - with any luck I'll find much lower miles dimmer switch.

And practice taken off the steering wheel on a rig where it doesn't really matter.

Anybody heard of a bad dimmer switch doing this?.

[EvanGrande]

Welcome to the forum! That combo/dimmer switch is almost certainly your culprit - the "only works when you hold pressure on it" behavior is the classic giveaway. One thing worth ruling out before you spend the afternoon at the boneyard: a corroded ground or a tired headlight relay can mimic a switch failure on these older Benzes, so it's worth a quick multimeter check.

Curious what chassis you're working on? 400k on the body is seriously impressive. Hope the junkyard hunt turns up a low-mile switch! Let us know how it goes.