It is definately a bad ground, but remember, there isn't a ground wire on the cluster harness. The ground is completed by the center screw between the gauge pods. This screw captures a metal tab where the bright indicator bulb is located. If you don't have the correct screw, this can sometimes be an issue. The correct screw has a taper below the head that matches the taper in the cluster hole. This allows the screw to bottom out on that tab. If you have a screw that has a differnt head (as mine originally did) it will still fasten the cluster pod tight, but it won't capture that tab to the dash correctly and can result in an intermitten ground.
I know that washing and waxing my car with the present condtion of my paint is like polishing a turd.....but it's my turd and I want it polished!