Bouncy Gauges
 

I've been driving the car all week after the DME fix and yesterday my gauges started to get jumpy, especially the temp gauge. If I turn on the headlight it will jump up about 4 mm, turn signal will cause it to bounce in unison, basically anything electrical in the car seems to directly effect the gauge. I've recently cleaned main ground and pulled instrument cluster a while back and cleaned footballs, changed lights. Any other grounds I'm missing or common shorts??

Give all the ground points a once over. That solved most of the issues i had with erratic gauges on my '87 n/a. The final fix was replacing all the of the battery cables.

Check out this thread i made with specific details on each grounding point.

http://forums.pelicanparts.com/porsche-924-944-968-technical-forum/422736-late-interior-groud-point-locations.html?highlight=grounds

Thanks, that's actually the thread I read when I originally did the grounds. Are there two in the rear hatch because I could only find one(two shown on diagram)? Also, it looks like your 951 has a ground by the ICV bypass and the cruise control module that aren't present in the NA. If that's true, I cleaned all grounds. I guess battery cables could be it, it's strange that it's only affecting the temp gauge???

The grounds by the test port and cruise module are actually only for the brake pad wear sensors.

Double check the leads on your water temp gauge. Give them a good cleaning and make sure the wires are still intact. The spade connectors were pretty badly corroded and the insulation had cracked off. I cut the bad portion out and soldered in new wires with spade connectors.

Pad wear sensors, huh. I wonder where mine went? I tightened down the temp sensor spade connectors when I had the manifold off a few week ago but the wire did look pretty beat. Man that thing is hard to get at with manifold on!! There's got to be a wire or something loose somewhere, the problem is finding it. This past week was the first time I really drove the car consistently so maybe something just came loose- now that I think about it the car was hard to start yesterday and today (four or five cranks). All week it was starting on first or second crank, could be related.