The Temp guage on the above GMC van was not working, it was
practically pinned on the hot side. I went to the auto wrecker and
grabbed a cluster out of a late 80s model, and bought a brand new
sending unit. Replaced both, no difference. I'll also mention that the
gas guage and oil pressure guage are pinned as well. Not worried about
those as there are aftermarket fuel (propane) and oil pressure guages
that work fine.
Anyway, what would cause the temp guage to read so high? I noticed
that as the engine warmed up, the guage would show even higher, so it
is having some change, but way out of wack.