The good news is I found the problem. The bad news is I had to pull the cluster to to it. Of course the entire dash has to come out too.
With the cluster out I tested the temp gauge with a Dewalt battery to determine it was good. From there I traced outward to the contact point of the printed circuit and the connector. I discovered the run on the circuit had lifted and was pushed aside, not making contact. I repaired the run and solved the problem.
Yeah me! Now I get to install the entire dash again.
