https://mercedesforum.com/forum/ Mercedes SL500 and Mercedes SL600 Roadsters. en Wed, 20 May 2026 18:36:40 GMT vBulletin 60 https://mercedesforum.com/forum/images/kirsch/misc/rss.jpg https://mercedesforum.com/forum/ https://mercedesforum.com/forum/mercedes-sl-class-15/workshop-manuals-500sl-r129-69011/ Fri, 01 May 2026 19:08:54 GMT My car is a 1991 500SL R129 Many years and MANY computers ago, I purchased the R129 STAR Class Service Manual Library discs. As I said, that was many computers and operating systems ago. Now I... My car is a 1991 500SL R129

Many years and MANY computers ago, I purchased the R129 STAR Class Service Manual Library discs. As I said, that was many computers and operating systems ago. Now I have a problem with the car and I cannot get these manuals to install, so I am flying blind.

I see there is a lot of on-line services for manuals now. Are any of them any good? What is everybody using?

Thank you. ]]> Mercedes SL Class tedbenz76 https://mercedesforum.com/forum/mercedes-sl-class-15/workshop-manuals-500sl-r129-69011/ https://mercedesforum.com/forum/mercedes-sl-class-15/1991-sl500-low-beams-not-working-69010/ Fri, 01 May 2026 18:01:06 GMT 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... 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? ]]> Mercedes SL Class tedbenz76 https://mercedesforum.com/forum/mercedes-sl-class-15/1991-sl500-low-beams-not-working-69010/ https://mercedesforum.com/forum/mercedes-sl-class-15/sl-r230-fuel-flap-cover-68984/ Fri, 24 Apr 2026 07:50:46 GMT I have a SL R230 NIGHT EDITION 350 2010. Recently after taking the car through a SAINSBURYS car wash in the UK it opened the fuel cover and flicked it off. it has done this twice now. I now put... I have a SL R230 NIGHT EDITION 350 2010. Recently after taking the car through a SAINSBURYS car wash in the UK it opened the fuel cover and flicked it off. it has done this twice now. I now put some duck tape over the cap before the wash, if you forget then check after the wash to see if the flap is still OK. I was surprised that the flap just clipped back in place as the forks holding it could have been broken. This could apply to the R 231 and other models.

Captain Mike. ]]> Mercedes SL Class Captain Mike https://mercedesforum.com/forum/mercedes-sl-class-15/sl-r230-fuel-flap-cover-68984/