Speedo/Tach dont work. Weird Issue
 

I am trying to trouble shoot my friends cluster on my car. All his lights work and so does coolant. The odometer lights up, but no numbers are displayed. The tach and speedo dont work at all. But, here is the strange thing, if I turn the wheel to the left or to the right, the tack goes from 0 to 500 instantly, then back to 0. Any help?

Thanks!
Bryan

Sounds like a bad ground. Check the battery and make sure the negative cable has a good connection.

If you can get to the back side of the cluster you can run a ground wire from the top tach screw to a ground point on the chassis.