Why don't you download the 69 Dodge service manual free from this thread, so you can see the wiring yourself? It will also help with other parts of your car.
http://www.forabodiesonly.com/mopar/showthread.php?t=244981
BINGO and you can look at the back of the cluster and trace things out. The pin on the cluster which feeds the IVR is the broken pin to the right in the bottom photo
In the top photo, the left IVR terminal is ground, see the screw at very top? The blue is the copper trace. The two black wires are added grounding pigtails.
The far right IVR terminal hooks to the stud at bottom right in the photo. This is one of the gauge studs. Follow that again in the bottom photo. The blue trace connects the left and the third stud from the left. These are the IVR outputs feeding both the gauges.
Power, then, (top photo) comes into the center IVR stud. If you follow that trace off to the right (bottom photo) it goes to the third connector pin from the right, the broken one. I actually just abandoned the connectors on mine, soldered pigtails to the board, and used "Molex" style connectors to replace the originals
As you can see, I'm a cheap SOB. The small wires connected to the "ammeter" studs are actually the voltmeter.
NOTICE the IVR socket. On mine, those brass fingers WERE NOT making good contact with the PC board traces, hence, soldering the brass contacts to the board traces.
