how to bench test a 70 Dart instrument cluster?

turned out in the end to be 2 things - the original transistorized IVR (voltage limiter) that I got with the new circuit boards from Charger Specialties was toast. fortunately it has a test light built in so finding it faulty was easy. With a new IVR from RTE that tested correctly, I found out the new fangled gauge replacements that I got from Herbs did not work even with the good transistorized IVR, but a pair of 52 year old gauges worked just fine. All the gauges are working fine now. We'll see if Herbs and Charger Specialties will take the non-working stuff back. (by the way the temp gauge from Herbs had the scale printed too high on the gauge face - something not obvious until the whole unit was put together)

One of the most important diagnostics tools that Dana67Dart put me on to was using a gas tank sending unit to test proper function of the gauges on a table before installing instrument cluster in the car. There is a diagram in post #11 and you just hook the sender up in series where it shows resistor in top right corner (brown). Move the float up and down to check gauge response. works on both the fuel and temp gauges. Top of post #11 shows the 12v battery I used to do the diagnostics out of the car. I would also recommend really absorbing the basics in the ancient video in post #4 - it really gave me a basic understanding of the system before I blundered forward any farther.