First of all, George, I hope you don't mind me using a pic of your engine...it's just so clean!
Circled is the part I refered to. If that is the part you replaced, then I'm thinking, (just assumptions on my part at this point), that you have a wiring issue. Loacting it could be a pain though. It could be the wire itself or even something to do directly with your dash. I can't say for sure. At any rate, that is the part I was refering to. Not sure if this helps, but hopefully it will clarify.
Edit: Just for further clarification, there should also be a wire with a 'boot' connector that goes on to the top of the temp sending unit. Over time that wire becomes very brittle. Mine broke 3 or 4 times when I tried to fix my oil leak. New sending unit and an eyelet did it for me. At least for now. I'm hoping that when I rebuild my engine, I won't have to replace the wiring...hoping.