Found my dads original 1971 duster!

dads71 said
I’ll check again in the morning for a burnt wire etc. We looked pretty good today did didn’t see anything. A bad ground or a ground not hooked up couldn’t cause anything other than not working, could it? Not much was done right by the idiot builder. When we pulled the dash today he didn’t have much hooked up at all. Damaged vent cables, broken Speedo cable that wasn’t hooked up, radio not hooked up, no speaker, ground wires not hooked to anything. Crazy. He said that the dash and electrical was completely done. Lol

Oh boy!

The later panels like yours may have more grounds than my 67 but the three I mentioned are the ones I know for the interior.
In theory the instrument board will be grounded simply by mounting it, but at least on mine I found the factory had ground wire from the capacitor mounting screw to the radio support strut. I didn't see cap on your dash. I *think* it may not be needed if an electronic IVR is installed.

Loose wires - broken connectors. Any of them could have been a short, or a short waiting to happen.