Thanks to all who posted answers to the following threads:

No high beam indicator, and either no high beams or no low beams 200 1990
http://www.brickboard.com/RWD/index.htm?id=1153147

high beams won't stay on 200 1990
http://www.brickboard.com/RWD/index.htm?id=1156782

I took the one I thought was bad - no high beams and no indicator - and played with it a bit. It really is a very cool little mechanism! I decided to take a picture of the insides to the donor one - high beams won't stay on - before I cleaned it up and tested it. Even though it's in gif format, the forum image upload site is stating that:
The image must be of type jpeg(jpg), png, or gif. The type is:(21733)
If anyone knows how to resolve that, I'll be glad to post the photo. Here's the text that's supposed to go with it:


This is the what the inside of the headlight stepping relay looks like. This one is off an '86 240, but it is visually identical to the '90, which I've already restored. Make sure the battery is disconnected, as there is a live connection for the flash function.

There are 6 pinches in the aluminum case that isn't pictured - gently pry apart with a flat-head screw driver.

The little round copper contacts that activate the switch can become corroded, in addition to the exterior electrical connector prongs. I cleaned all surfaces with a dremel wire brush (variable speed 4-5), and then sprayed with electrical contact cleaner.

Clean the female receptacles on the wiring harness with electrical contact cleaner, remount, and reconnect the battery cable.

Check to see if it works before you replace the aluminum housing. Make sure you remove the battery cable before removing it or remounting it. (Can you tell I forgot to do this? Zap! Zap! Arc!)

Remove it from the harness. Repinch the aluminum housing with either wide pliers or a the side of a narrow chisel with a hammer (gently, please).


I hope this helps! Thanks so much for all the input!

I think I can, I think I can, I think I can get Junior on the road!
ezsha