Mercedes Benz repair: Instruments not working properly, southport nc, fuel gauge

Question
1985 Mercedes 380SL 152,000 miles Southport NC.
Odometer stopped working so replaced 3 gears. in order to fix odometer had to remove the instrument panel. Once I replaced the panel the odometer, speedometer and tack all work fine but it appears that there is a short or grounding problem because the fuel, oil pressure and temp gauges do not register correctly. Also, if I turn on the headlights with the ignition off, the fuel gauge moves. When I turn on a turn signal the gauges move back and forth with the blinking and the turn signal indicator on the dash does not flash properly but other light indicators (i.e. seat belt light) blink. The electrical connector on the back of the instrument panel can only be attached one way, so I do not see how the connection could be incorrect - in fact I have tried to force it over one pin position in each direction and can not get it to fit. Any suggestions?

Answer
Answer:
Your cluster ground wire is broken, and other devices are back feeding, in search of any ground.

Look through this list, there are several links that will help you.


Body Electrical:
http://www.mercedesshop.com/shopforum/showthread.php?t=142413