Part Number: 201 540 0845

Most MB parts shop call it a relay, some call it an idle control relay, and some say it could also be called an Overload Voltage Protection Relay (OVP). What exactly is this called? And can I use it in my W126 (280SEL)?

Secondly, what is the primary function of a relay?

Thirdly, can I still drive the car if a relay (say, the idle control relay) has failed?

And lastly, what are the typical symtoms of a faulty idle control relay?

Hope to get my data cleared up, I'm getting rather confused. Many thanks!

Mervyn
W126 (280SEL), 1983

That is the over voltage relay!
To protect computers from voltage spikes.
On that year EURO car, I think the only computer that it supplies power to is ABS.

Mervyn, that is still a good part number, and as M.B. Doc already told you it is the overload protection relay. I found it listed for 1981-87 380 SEL for $45.00. Does your 280 have one already or are you trying to add one????

Many thanks to MBDoc and Super Turtle, I think i'm on the right path. :)

Super Turtle, main reason why I'm so eager over this relay is: I have read that it controls the fuel system as well as idle control, of which both I'm experiencing some minor hitches. I hope that by replacing this relay, it would be a first (and hopefully, positive) step towards smoothening out the idle and fuel delivery. My 280SEL is a 1983 car, and I suppose there're some wear-and-tear items to replace.

The only problem is, I am not exactly very sure if my car has this relay. I have gotten conflicting opinions, both from this forum as well as from different mechanics here.

If there is one, I would like to replace it.

I'm still trying to find out, and I appreciate all your help, thanks!

:) :)

Mervyn

my over voltage relay is in my fuse box it has a fuse on the top of it..mine is in the back of the fuse box. It looks different from all the other relays..some are silver and some are black..this one is silver with a fuse on the top.

benzat
1982 380 SEC

Like MBDoc said, your 126 body 280 would not naturally use that relay for engine management. It depends on what was done to the car to "Federalize" the car. The 280SEL til 85 was a simple K-Jet system similar to 450SEL between 76-79 in the US. The only electric component is the fuel pump and the warm-up pressure regulator. The fuel pump relay poweres them. Most cars imported had lambda control systems added but they very seldom used MB parts.