cluster/gauge lights work when they want too

[hamburglar]

hey (yes I did search)
My speedo and tach sometimes, when I turn on my lights, will not illuminate. I always am able to get them to work by smacking the dash and they will eventually kick on. Last night I had to pound on the dash to get them to work lol.
I took out the instrument panel and checked the connections behind it and put electrical grease on all the connections to ensure that isn't the problem. Then I left work today and noticed that the high beam and rear window heater indication lights illuminate fine.

Its is a 90 so it has back lit green gauges and also a light shining down on the gauges. Neither of those lights (back lit and shining down) work when they go out.

Any ideas on where the bad connection could be?

[fastivaB6TG25MR]

good luck... let me know if you find it... been looking to fix mine since i got my car 2 years ago...

[Pgh5spd]

For some reason, seating the plugs into the instrument cluster is tricky. I just had my recently-installed tach cluster out for the third time to get the gas gauge working. I was sure I'd gotten seated the one (LH) that feeds the gas gauge, but when it pulled the cluster out today it just pulled off without pressing the tab. I have one cluster that has a broken center shaft for one of the plugs (or whatever you want to call it; probably broken by some impatient idiot who couldn't figure out how to release the wire feed) so you can't get it to click in place anyway. That doesn't seem to be a problem as long as it's pressed in all the way.

To release these things, if you haven't memorized the drill, you press the tab in the center toward the outside with your LH thumb against the square boss (raised part) on the side of wire feed cluster.

Anyway, I've been thru this drill before. Once you get it seated well, it should last for a long time. It's just hard to tell when it's seated well.