!992 500SL Continuing Problem!

[Tom McMenamin]

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I have a friend who has a 1992 500 SL and he is experiencing a continuing problem and continuing expense with his Air Bag sensor dash light.

It began by flickering and he had it repaired, it then stayed on for short terms and he had that repaired, it is now on all the time and before he spends more dough on the same problem I told him I would poll the board for some suggestions.

It seems that I have read a response to a similar problem on the Board but for the life of me I can't get it to come up in a Search.

Anyone have any ideas on what to look for or ways to get the dealer to ultimately solve his problem?

[suginami]

I believe air bag sensor lights (SRS) are usually caused by a bad switch in the seat belt latch.

I had a similar problem in my '86 560 SL. I don't know if the cars are the same but here's what they did to fix mine. Behind the seat where a jumper seat would go on the vertical part there is a a capacitor can fairly large, with time this part can oxidize and rust breaking the electrical connection for the air bag. My mechanic replaced the part and it was solved. He also told me Mercedes had a bulletin and suggested that the canister be installed with the electrical connections facing downwards. Hope this helps.
Larry

[DanielG]

Hi -- I have a 1986 560sl with this problem -- I would like to check this out -- does anyone know the correct name for the part and/or the part number? thanks!

[Momo]

This may be related. On two occasions (with my 1990 SL500), when the windshield was dry, I have had the wiper stall in mid-stroke. When it did this, the SRS light came on, then went out again after the wiper continued. I therefore suspect that they are on the same circuit, and that when the wiper motor draws too much current, the SRS light can come on. Unfortunately, I have not been able to reproduce it when the car was stopped.

Momo

[BobH]

Tom,
When my 1990 300 SL had the same symptoms, the dealer diagnosed the problem as the SRS Control Module - For Airbag & Seatbelt. The module was replaced just about one year ago and I haven't had the problem again. Tell your friend to try everything else first. The module cost $1281.00 and the labor is about 1.5 hours.

Bob

[bobterry99]

You can easily check for diagnostic codes for the SRS that may help pinpoint exactly what is causing the light to switch on. Mine was on due to a faulty seat belt latch switch, which Paul notes is a common problem.