w202 intermittent healight issue
 

1995 C36 with 160,000 miles. My headlights work about 70% of the time. When they fail the parking lights do still work but holding the high beam lever back does not work. So I'm guessing its a relay and not the switch.

Where is the relay located and is this a common issue?

Its been hard to test because they always seem to go out at the worst time when I can't deal with it and then work when I have time to look at it. :mad:

There's no relay. Do both sides fail at the same time? When the lights fail, if you pull the knob out will the fog lights go on?

Yes both sides will cut out at the same time. The parking and fog lights still work. I mean there has to be a relay somewhere. The switch doesn't have full power running through it.

Here's the diagram. Good luck finding the relay. I don't see one. I would say it is the light switch, labeled 40 on this diagram, but in that case, when you pull the dimmer lever toward you the brights should still go on, although they would not when you pushed it forward.

It was the switch. Swapped it out with a junkyard part and it seems to be good. It must have some weird contacts in there.