Help me troubleshoot my temp gauge please!

[fishmunger]

So I've searched and read about every thread I could find on the subject. Here's where I'm at.

Gauge is pegged at hot.

I have replaced the half of the green wire that is in the engine bay and added the correct brand new connector that goes onto the temp gauge itself.

The previous owner had put a brand new sending unit in (at my request) right before I bought the truck (and it looks brand new).

At the advice of some threads, I added a little extra grounding wire on the back of the temp gauge itself. When I did that, I briefly got the gauge to 're-set' back to the cold side but then I hooked it back up it pegged hot again. I can no longer get it to re-set.

When I ground the end of the temp sender wire and turn the key on, I can see the gauge needle move a little bit (but still stays pegged on hot side) - this leads me to believe that my gauge is working?? Underneath the dash, I can't see anything abnormal with the wire that would lead me to believe its shorted. It's still in what appears to be the original harness/taping.

Any ideas, this is the last thing keeping me from having this baby back on the road! It's been down almost a year...

Thanks!