I had an original unit restored. The voltage regulator was a problem as well. Sometimes the problem is right in front of your nose. it makes it so easy to overlook.
I'm glad you have it sorted.
Did you replace the voltage regulator? Which one did you use?
I have a nice functioning temp gauge but now the fuel gauge dropped out. I have to do a wiring routing check.
I suspect that I have a bad sender wire through the rocker panel.
The fuel sender isn't new, but it was replaced with a Ford unit before. I have not pulled it out of the tank to check it.