I tried the search and nothing useful came up. Is it a common problem, or am I gonna have to get in the dash and dig around?

I've got kind of the same problem. My tach doesn't work until the car warms up a little when left outside in cold weather but works fine if I leave the car in the heated garage overnight. I dug around in the dash and cleaned the connectors on the instrument panel but it didn't get rid of the problem. I think the tach is triggered by the crank sensor (I may be wrong about this) so that's gonna be the next thing I check.

If you figure out your problem, please remember to post your findings. Thanks.

I have 2 saabs 9000s that are doing the same thing. They just wear out and don't like to work some times until the car warm up. I have tried everything to get it to work with no luck. I have just learned to live with it.

So it's a mechanical screw-up?

Well, Hell! I'll get another one and swap it out. Admittedly, it's more of an annoyance than a problem but it drives me up the wall when something that's supposed to work doesn't. :nono;