Sluggish, rough idling 380SL cured! Over voltage relay - PeachParts Mercedes-Benz Forum

Alan S · #1 10-23-2015, 11:24 PM

Had to reemphasize the importance of the over voltage relay. Recently purchased a rough running, and sluggish 1982 380SL. Took it to an independent shop where they diagnosed the problem as several large vacuum leaks and a faulty warm up regulator, estimate close to $2k. I said no thanks and took her home. After reading several threads, I decided to start with the over voltage protection relay, and to my surprise, the 10amp fuse was split. Replaced the fuse and astonishingly all the roughness and power loss disappeared! In fact, I took the car on a 250 mile trip today, ran 75-80mph the whole way, with plenty of power on tap. Now, I'm not saying the car is a speed demon, but if I ever get around to fixing the vacuum leaks, I might actually consider the car "sporty". Thanks to the good folks on this forum and others that lead me to the over voltage relay...Alan

IggyAZ · #2 10-24-2015, 09:36 AM

I have a 1991 300SL and was wondering is the overvoltage relay and fuse is located in the same location as yours.
I think mine is located in the engine compartment passenger side rear with a large cover.
Is the fuse also locate dint hat location or in one of the fuse panels?
Thank you

Alan S · #3 10-25-2015, 08:07 AM

I'm sorry but I wouldn't know? We have a different body. Mine was located behind the fender on the passengers side, above the passengers right foot

JimRockford · #4 11-14-2015, 12:40 AM

Alan, I assume you took it to Manfreds?

I live in Cary as well. You might have seen my red '76 450SL with the plates EWNG 4.

Benz Mondi · #5 11-14-2015, 01:33 AM

Quote:

Originally Posted by IggyAZ

I have a 1991 300SL and was wondering is the overvoltage relay and fuse is located in the same location as yours.
I think mine is located in the engine compartment passenger side rear with a large cover.
Is the fuse also locate dint hat location or in one of the fuse panels?
Thank you

Yes. You are correct. It's under the large panel. Here's a picture of the area underneath the panel. The OVP is at the left corner of the pic (red top next to one of the MAS relays). This was the dusty and dirty condition I found my car in when I bought it last Xmas. I've since thoroughly cleaned it up so it's nice and sparkly clean!... hate to have dirty engine bays in my cars.