Fuel Sensor Relay Failure Rate??
 

My 380SL has been in the body shop for over 4 weeks (long story) and now all of a sudden the fuel sensor relay under the dash has failed. Does anyone know of the failure rate of these relays/sensors? Sorry if I'm not too concise, however, the Mercedes body shop wasn't all that clear either. All they said is that it quit while there and then they had to replace the part? Could this have been accident related? I was hit in the rear at 55 mph. OUCH. Please let me know if anyone knows of the failure rate; so I can convince the other guy's insurance company to pick up the $300 tab on this thing.
Thanks.

Sounds to me like someone may have been confusing the fuel pump relay under the passenger-side dash with the sending unit under the clear, plastic cap in the soft-top boot compartment. The relay does tend to fail, and would prevent the car from running, but I can't see how being rear ended would cause it to fail. I suppose the sending unit could be affected by a rear hit, but if I'm not mistaken, that unit simply sends the fuel level info to the fuel gauge.

OTOH, the fuel pump, filter, and accumulator are all tucked away under the car's rear. So, being rear ended could have definitely done some damage to any or all of these. But, then again, I wouldn't trust a body shop guy to diagnose the problem unless he was affiliated with a dealer or Indy. BTW, if it is the fuel pump relay, it's about $100 and very easy to replace. The sending unit is also easy to replace, but it's over $200.)

Good luck!

Sensor
 

It is at the Mercedes Dealer, I refused to have it "farmed out" to a different body shop and wanted to make sure it was where they all all Mercedes parts. The body shop guy said that the mechanical shop is where it was diagnosised, I guess I'll wait until I go down Monday to pick up the car to see exactly what it is supposed to be. Supposedly the part was $195.00 and they charged $100 to troubleshoot and repair. This was done without any call to me other than to tell me it wasn't running. So, we shall see what happens when I arrive there Monday. My husband has over 50 years experience as a mechanic so I'm sure he will have a discussion wiht the personnel there. Thanks.

Additional Question
 

Does the fuel pump relay fail often enough that I should carry one with me?

Thanks.

I would complain about a total of $100 labor to diagnose and install, plus list price for the part. Whether the fuel pump runs is like the most basic thing to check, and all you have to do is put your hand on it while someone cranks the starter. Then it's about 20 minutes to drop the dash panel and replace the relay and put the panel back.

The relays seem to fail randomly. Personally, I carry a piece of #14 wire to bridge the contacts in the relay socket if needed.

20 min. Does that include getting the work order, getting the car from the lot, returning the work order and returning the car to the lot. We used to get 0.6 for an oil change. Very difficult to do the job in 0.6 unless it was already in the bay.

John Roncallo

I couldn't find a number for fuel pump relay replacement in Alldata, but for a couple of other relays in the footwell area, it's .4 hours. The car was, kind of sort of already in the shop for the accident repair.

Isn't the overhead generally built into the shop labor rate ?

Speaking of relays, I just happened to notice in the Performance Products catalog that the 450sl, the 560sl, and every 380sl except the 81 has an over-voltage protection relay, which also tends to go. Does anybody happen to know why the 81 380sl doesn't have that relay?