1984 300SD Instrument panel went dead
 

:(I inherited my dad's Mercedes when he passed in November. I didn't start driving it until March. It was his pride and joy and now it's havign issues. I drove it to work today and all was well, then halfway hoem tonight, the instrument panel went dead and I lost my turn signals as well. Any ideas of what I'm looking at for repairing whatever this might be. We don't have much money for repairs, but I have become very dependant on my dad's car. I would love to keep it running, but if it doesn't pass inspection in January then I will be forced to sell it for parts. It runs great otherwise.

Welcome to the forum :)

Sounds like a fuse issue. Open the hood and there is a flat plastic panel which is behind the firewall next to the brake booster. Inside are the fuses. Check to see if the metal strips on the fuses themselves are burnt and therefore not providing electrical current.

When you stated the instrument panel went "dead", are you saying the lights went out or that it no longer indicated engine parameters, speedometer, etc.?

diam... is correct, check fuses. The symptoms you described are related to fuse #12 an 8 amp white one. The fuse #'s are marked on the plastic housing, the ones closest to rear of car are difficult to see, #12 is in front. This fuse is for your tach also. Welcome to the wonderful world of MBdom!

1984 300SD Instrument panel went dead
 

I have the same problem with my '80 SD that I just purchased. The fuses seem OK. Looking at the electrical schematic it seem that the power for theses items originates in the ignition switch and then goes to the fuse box. Could it be the switch?
Gary

If you have any suspicion that the fuse is the issue, you must replace the fuse. Looking at the fuse and determining that they "seem OK" is not sufficient. The failure mode for most of these fuses is a very tiny crack across the element........not visible. Sometimes, the fuse will fall apart when you remove it from the holder.

Replacing all the fuses is a wise move for anyone with an older vehicle that has questionable maintenance in the past (90% of them).

I had the exact same problem with my 84 SD and the fuse looked great, until I took it out of the holder. That's when I saw that the end of the fuse had flaked away and there was nothing making contact with the holder.

Right Here -----> :<======>:

Take the fuse out and inspect it. You will be very happy you did.

A variation on the instrument panel lights question: on my E320 wagon, 1994, the lights come on only sometimes when the head and/or parking lights are turned on. If they come on, they stay on. But mostly they don't come on. The lights on the center panel (a/c, gear shift position, etc) do come on every time, and they change brightness if the rheostat knob is turned. So the rheostat is presumably OK. What is it that would cause this intermittent failure of the instrument lighting, but not affect the lighting of the center panel? I haven't pulled the instrument cluster yet, because I don't know what to look for.

Guidance much appreciated.

Peter Bakewell

Hey I just want to thank diam for the heads up, I pulled the panel open and checked the fuse corresponding to the problem and it was bad, just so happened to have new fuses stored in front and changed it...works just like new again!! Thanks so much for the help...now on to bigger and better problems (i.e. back passenger window halfway down, will not go back up, rear right shock blown) I gotta get both of these things fixed. Goodyear wants to charge me $319 for the shocks installed, and a gentleman running the European Service Center here in Leesburg wants to charge me $300 to fix the window...anybody think these numbers sound right?

Glad that fixed it. It's nice to start with the cheap fixes and go from there. :)

I would definitely carry some extra fuses Blue White and Red in the glovebox. They burn out at inopportune times and you'll be much more relieved that you have some spares when they go.

As for the rear passenger window do you hear the motor whirring when you toggle the switch or is there no noise at all? There is an item called the "sliding jaw" that breaks the linkage between the motor lift and window itself. It's a cheap part but it's a pain to replace. The window shouldn't pencil out at $300 (3 hours) to replace the jaw unless the motor is shot. A used one can be obtained by somoene here on the forum for much less than a new one.

As for the shocks that is a little pricey. Each part is $75 so therefore $150 in parts and $150 in labor is about 2 hours. It can be changed in about an hour with a good lift.