Originally Posted by timothale
I forget what it was caused but a lot of Fords used that little box on the back of the cluster about and inch and a half long, 1/2 wide with2 wire stud terminals ? UPDATE... it's called a constant voltage unit. you might have to wire one in if your donor cluster had one.. For Wiring Fords before the computer digital units I use early Mustang wiring diagrams. Google Hammar mustang wiring diagrams, I don't know how to give you an easy link.
Drats, the back of the gauges did have a small box maybe 1 inch by 1/2 inch, stupid thing did not have any studs though but was instead wired into the sheet of ( what do you call it ) .......that electrical tape stuff with all the circuits running through it.
I will have to look into this further, thanks