'86 420 SEL Instruments Problem

[Randy]

Hi, guys, I changed out my broken odometer gears (thanks, Jeff Caplan) and I have the instrument panel back together. Now my oil pressure and temp gauges aren't right. They all do something, but the temp gage goes to max and the oil press gauge reads too low: about half way when driving, zero when idling, and it has a slight jigglr about once per second. The gas gauge seems right, as the tank is full and it goes to full when I turn the key on.
When I removed the round harness plug from the left side of the panel, the index pin in the center of the plug broke off, so I superglued it back on; otherwise I had no problems. Before I began this repair, the only prob I had other than a non-working odometer, was maybe the oil press gauge: it would peg at idle when cold or driving at any speed above idle; on warm idle it ran about midway, with a jiggle about once per second. I did not know if this was normal for the oil press gauge, but it aalways was like this as long as I owned the car. Advice?