Gauges work intermittently

Has any one had a problem with tach or temp gauge working when they feel like it? tach reads different rpms at same speeds from one day to the next, temp gauge works or it wont, all the gauges in the cluster sit flat lined for the first 20-30 seconds after starting the truck most of the time.
Any thoughts or similar problems?

 

Maybe the plug in the back of the cluster is loose.


I had this happen in a 93 Toyota Pickup with just the tach. It would fluctuate at a constant engine speed. It was either the electronic tach itself, or whatever sent the signal to the tach. I'm not sure what those trucks used.

 

take the two plugs out of the cluster and put some dielectric grease on them

 

You know what that happens to the lights behind my odometer.