1982 ea81 glf 2wd coupe. so here's what's going on, volts, fuel and temp gauges start to work but don't read correctly, also my a/c compressor will not engage when I select. I can jump power to the switch and activate. my fans also see to be having this intermittent issue, now they all worked at one time and dwindled off. my question is what the the common circuit. maybe I need to go through and clean the main ground. I have had this engine out a few times. my dome light does not have power.. and my oil pressure gauge shoots to max as soon as ignition has power. and ideas would be great.

Does sound like grounding issues. There is a ground for the front section of cabin wiring under the driver's side of the dash. It ground through one of the screws that holds the hood release. The engine bay harness has a ground near the battery, and the rear section of cabin harness has grounds under the passenger seat and in the trunk. Those are the ones that I can remember off hand. There may be a few others as well.

 

Overall these things weren't grounded as well as they should have been. Check and clean every ground you can find.