Sudden Electrical Issue - PeachParts Mercedes-Benz Forum

UriahT · #1 04-19-2009, 08:31 PM

Driving the '81 wagon home tonight (2hr drive), I noticed that my fuel level was at 0. A little panicked, I then noticed that the speedo and temp gauge were also at 0.

So, upon further (very fast) investigation, I noticed all the following electrical equipment didn't work:
-Windows
-Side blinkers
-Rear lights
-Fuel, temp gauges
-Speedo and odo ('81 wagon has an electrical speedo, not a mechanical cable)

But the following works fine:
-Headlights, foglights
-Clock
-Dash Lights
-New Backup lights
-ACC, blower
-Radio
-Glow plugs, starter
-Car seems to run fine, oil pressure (mechanical) reads fine.

I took a look at all my fuses, and they look fine (will replace when it's light out). But I know a # of these items are on different fuses. Had the alt replaced a few weeks ago, and I know that and the battery are in good health. Ground points are ok, including the main to the trans bell.

Not an electrical genius; has this happened to anyone else? Curious how some things work fine and others not at all. Is there a relay I should be looking for, or a "master fuse?"

Thanks for any help, it's got me good since I don't pine for the idea of doing the NJ turnpike w/o side blinkers or tail lights, for one.

SD Blue · #2 04-19-2009, 10:53 PM

Hmmm.....key switch maybe? Try moving the key back and forth slightly and see if there's a change.

UriahT · #3 04-19-2009, 11:29 PM

I tried jiggling the key around in all positions... doesn't seem like a lot of play, and it didn't affect the electrical issues.

Also, add to the list, dome lights do not function. Hope this doesn't happen to anyone else!

rummur · #4 04-20-2009, 04:41 AM

If I was trying to figure this one out, I would turn the dome lamp on, then start jiggling wires under the dash on the drivers side. hopefully the dome lamp will flash when you get close.

good luck.. its probably a plug that has come loose?

SD Blue · #5 04-20-2009, 11:25 AM

Their may be something that came loose in the fuse box. Disconnect the battery first! Look on the back side of the fuses and see if any wiring is loose or any screws have backed out.

My first suspicion would be fuses if you have the cheaper aluminum type as they are notorious for intermittent problems.

leathermang · #6 04-20-2009, 01:17 PM

Also check the other side of the circuit... the shared grounds for these items....

UriahT · #7 04-23-2009, 02:50 PM

Well, let this be a recommendation for everyone who owns one of these cars:

Change all your fuses.

I had not 1, not 2, not even 3 but 4 bad fuses.
Best $8 I ever spent to replace each and every one.
This of course after they all "looked" ok, and I spent a couple of hours juggling around wires under the dash.

kerry · #8 04-23-2009, 03:31 PM

Quote:

Originally Posted by UriahT

Well, let this be a recommendation for everyone who owns one of these cars:

Change all your fuses.

I had not 1, not 2, not even 3 but 4 bad fuses.
Best $8 I ever spent to replace each and every one.
This of course after they all "looked" ok, and I spent a couple of hours juggling around wires under the dash.

How would 4 fuses all go bad at once? I'd suspect a common cause.

UriahT · #9 04-23-2009, 04:07 PM

Quote:

Originally Posted by kerry

How would 4 fuses all go bad at once? I'd suspect a common cause.

You know, I think they were all just real shoddy at the ends (the part that you can't see when you just glance at them).
That coupled with a lot of dirt road driving and having the car up and down on jacks all weekend might have done it.
If it comes back, I'll investigate further, but I'm just relieved to have blinkers and a speedo...

tbomachines · #10 04-23-2009, 04:14 PM

I've noticed the fuses get quite a bit of gunk and corrosion on them, which leads people to believe that their fuses are ok by sight (the metal strip is intact) but not making good contacts. Keeping a fuse kit in the glove compartment is always a good idea too.