Help Please - Electrical Problems '91 300SE - PeachParts Mercedes-Benz Forum

Bruce B · #1 12-04-2002, 09:45 PM

I have read a few threads that said sometimes a problem may be tied to a seemingly unrelated system. Here's mine; no radio power, no rear glass heat (switch lights up), no front interior light, no front passenger door courtesy light (the other three work), very slow heater fan (if it works at all, figure a new fan motor is needed). When I bought the car last week I replaced a blown fuse and got the seat memory and the three courtesy lights back as well as the ashtray light. This is a minor glitch for me as the running gear is more important (runs smooth, fast when needed, and I'm getting about 20 mpg or so. The only other problem I have discovered is that it needs a front end alignment (again a minor glitch). Let me also thank whoever started this site as I have found many ideas to make my Benz a better, sharper looking one. : cool:

Mike Murrell · #2 12-04-2002, 11:02 PM

There are all sorts of variations with regard to interior illumination in the 300-SEL that are controlled by a switch that's just above the rear view mirror. I'd experiment with the settings and see if you can recover what's missing.

The fuse box is under the hood on the drivers side up towards the firewall. This car uses ceramic style fuses that aren't always available at all parts houses. Over on the Ritter-Easley list, there's a following who believe that ALL fuses should be changed out from time to time whether they appear to be working or not. Sometimes these ceramic fuses appear to be intact, but are not seated correctly.

The slow running fan may be indicative of worn brushes or quite possibly, the cars battery is starting to grow old.

Love those 300-SELs !!!

Bruce B · #3 12-04-2002, 11:58 PM

Thanks Mike. Looks like a fairly new battery and I got two packs each of the different fuses from parts store. I'll check the fuses with a meter to see if.... Motor brushes eh, sounds a lot better than a new motor, when it does work it makes a rumbling noise.

maheath · #4 12-05-2002, 11:07 AM

I'm not on the Ritter-Easley list (their subscription form has been down for a long time), but I certainly believe in the "replace alll of the fuses" theory. When I did that in my SL last year, certain strange things went away, never to come back. I bought my 300SEL a little over a month ago and that was one of the first things I did to it. I still have some strange electrical quirks, particularly in the power seats. Sometimes they work and sometimes they don't.

For eletrical components in the doors, you might check the rubber accordian that protects the wires as they go from the body to the door. That seems to be a common problem.

When you can replace nearly all of the fuses for about $10, it doesn't seem worth the time to meter them. This is coming from a guy who will meter AA batteries before throwing them away.