"Gregtx"]On many of the electrical based clusters, Ford used this odd little device to step down the voltage from 12v to 5v to power the cluster. Those devices tend to fail on you. It looks kinda like a small relay and is to the far end of the cluster opposite to where the harness enters the cluster. You can take a multimeter and test the voltage coming out of that unit and it should read 5v. If there is no voltage, the device is likely bad. Mac's auto parts sells them, but I found it easier to just go to the 7-11 and buy a USB charger for your cigarette lighter and replace it with that. USB chargers put out a 5v signal and it's not terribly difficult to tear one of them apart and solder wires to the input and output. 12v in, 5v out. It's far more reliable than the stock replacement part (which I believe was basically like a small heater that provided resistance to step down the voltage).
The IPVR (instrument panel voltage regulator) I'd replaced the one on the dually I built with a universal adjustable.
That's a pretty kool shortcut I'll have to remember about the cell charger too!