380SL - Odometer replacement - now instrument problems - PeachParts Mercedes-Benz Forum

winstont · #1 08-27-2009, 09:03 PM

Good evening all,

I have a 1982 380SL and just had my odometer gears replaced. I had no problem getting the gauge cluster out, but I am surely having issues now. I put everything back together, put all the plugs in their proper place, started the car, and now my O2 light is on, the fuel and oil gauges go nuts when I turn the lights on, and my turn signal indicators are dimly lit at all times. When I apply a blink, the outside blinkers do blink, but the instrument lights do not change from their dimly lit state. Has anyone had this problem before? I would appreciate all help I can get in fixing this situation. Everything worked normal before disassembling the dash. Nothing was pulled out hard or wrong, and everything looks correctly assembled. Thanks for any help!

Winston

winstont · #2 08-31-2009, 07:20 AM

Does anyone know how this instrument panel is grounded? It acts like a grounding problem.

nhdoc · #3 08-31-2009, 09:32 AM

The ground is transferred from section to section by the mechanical connections (screws) which hold the sections together. Check for bad/loose/dirty ground connections and also check to see you don't have a burned up trace on one of the boards.

Also, make sure the big plug's indexing pin didn't break off and you don't have it connected wrong. I have seen that happen many times...the center pin stays in the hole and then you don't have it aligned right when it goes back together (it is one or two pins off). Check those items and you will likely fix it.

big dog 2 · #4 08-31-2009, 09:45 AM

Similar problem with my 1989 300E. Oil gauge dead with the tach and clock acting strange if the cluster was in place or was all the way out. However, if the cluster was half way out while in contact with the housing, everything came to life! I did get the cluster to work while in place in the instrument panel by mistake. I slid the Mercedes hook along the right side of the cluster in preparation to pull it out. This action somehow completed a connection somewhere and the entire cluster came back to life. Take the hook out and the problem reappeared. I repeated this over and over but cannot figure out exactly what is or is not making a connection. Sound type of grounding issue is what I suspect............................

big dog 2 · #5 08-31-2009, 09:48 AM

Just saw nhdoc's post.....makes sense to me! Now, where is the break in the ground........

winstont · #6 08-31-2009, 01:22 PM

Thanks to both of you for the suggestions. I will see if I can fix the problem when I get home. I'll keep you posted with my results!

winston

tinypanzer · #7 09-01-2009, 11:21 PM

In situations like this, as little as people like to admit it, the problem was introduced during repair. But that's a good thing, since you know everything you touched while in there you can easily go back and re-check everything. I vote for the busted index pin.