how to bench test a 70 Dart instrument cluster?

thanks Dana, I watched it once and will watch it again in the morning and I'll take some gauge pics then too and post them. This is a standard dash (long flat speedometer) so the IVR is plugged into the back and according to the FSM and tracing the circuit board the IVR only feeds the two non-functioning gauges (temp and fuel). Oil pressure is split with the original light functioning as it should and a mechanical gauge under the dash. The ammeter wires are disconnected from the dash unit and feed an ammeter gauge under the dash (along with a voltmeter independently wired). From the video it seems to be the voltage limiter that is the culprit since both the gauges that it feeds act the same. I don't think it is the IVR ground since the limiter ground uses the same ground circuit as the dash lights and they work properly. I'll follow the directions RTE sent to test the IVR.

Back to a previous question: Can I use a 12V lantern battery to power the cluster on the bench? what would I use as a ground?

I'm starting to really understand how this stuff works (THANKS!), but still don't understand how to mimic the resistance at the sending unit to check the gauges. This is resistance in the flow to ground, correct? OOPS OUR POSTS CROSSED - is there a place to buy one of the 3 resistor boxes?