This started a while back. First one low beam goes out and then the other. At first, they would come back on if I let the car sit a couple days. Now the low beams are out all the time.

The high beams work fine.

I cleaned fuse contacts. I installed new fuses. No change. Using a test light, I found there is no power to the low beam fuses.

Just to be 100% sure, I checked the headlamps, their wiring and the ground connections. All seems to be in order.

Then I put a jumper between the fuse for the high beam and the fuse for each low beam ... the low beams do work and do not blow a fuse. This indicates to me that from the fuse box to the headlamps, everything is in order. The problem is from the fuse box back to whatever control units, relays and switches there are.

As a part that commonly goes bad, I installed a new headlight switch in the dash. No change.

I replaced the lamp control module (129 542 01 32) with a used unit. This is the lamp control module (129 542 01 32) located to the rear of the main fuse box. No Change.

I removed the cover from the lamp control module (129 542 01 32) that was in the car originally. This module is a solid state and NOT a mechanical (electro-magnet) device. I have no way to test these units and have not been able to locate a new one.

Does anyone have a wire diagram for the light circuit? Many years (and computers) ago, I purchased the R129 STAR Class Service Manual Library discs. As I said, that was many computers and operating systems ago. I cannot get these manuals to install now, so I am flying blind.

Does anyone test and rebuild these lamp control modules (129 542 01 32)?

Does anyone know if the high beam switch in the steering column is known to fail?

Are there other components in the circuit that I am missing?

Although it's been suggested, I cannot find a reference to an "exterior lamp relay" ... or it's location. If there is such a thing, Could someone tell me where it is located?