Ahhhh...the well known (to some!) problem of 1969/70 gauges not working when replacing a circuit card. The gauges first pass through a small rectangular hole, then a cardboard rectangular piece fits over the two posts onto the metal housing, then the circuit card, then the two nuts which hold everything together. The problem? Any one of the gauges' posts can contact the metal housing without you seeing it, shorting all of the oil, water, and fuel gauges to ground, as they are all tied together with the CVR output. The ammeter is separate and MUST not touch the housing, as it will cause a dead short to either of the two hot and non-fused wires.
How to test? Unsnap the battery snaps on the CVR and measure the resistance from any post of the oil/fuel/water gauges to the metal housing. You'll either see something very close to 0 ohms or 14 ohms, depending upon which post is shorted. How to fix? Loosen each gauge up, reposition, and retighten. Test again. This is a PITA as you don't know which gauge is shorting. Better solution is to remove the circuit card, then the cardboard insulated pad, and line each rectangular hole with black electrical tape. Put everything back together and you should be good to go.