Wrenchbender:
You are correct, there is nothing insulating the posts from the mounting plate on the back of the gauge cluster that they pass through. I looked at the original gauge and it had a piece of cardboard between the back of the gauge and the mounting plate, but still no visible insulation between the posts and the mounting plate where they pass through the holes. i don't understand what kept it from shorting out against the gauge cluster through the post to plate connection. I'll try some rubber grommets, or whatever I can find that might work, tonight.
Red58 & Automarc:
I wasn't clear in my prior post. The side of the temp sending unit is grounded, as it should be according to the Shop Manual-there is good contact between the sending unit and the engine block. I will check for a resistance between the center post of the sending unit and ground tonight.
Thanks to all.
