Help with Temp, Gas, Oil Alt gauges FREE VIDEO INCLUDED!

I had typed inst" regulator in one place and simpy regulator in a another. I guess I should have typed IVR in both? Anyway, The system voltage regulator is not relevant.
We know you had a copper trace burned on the original board and we know that was the 12 volt supply to the original IVR. We know there was another wire tapped into that black wire and we know its now removed. What I don't know is.. was the white wire a tap out and tap in? Is your IVR getting 12 volts from that black wire?
You said you now have a solid state IVR. Is that the RTE brand? Does it have little LEDs on it? If so, and from what I've read about those, there should be one LED continuously flashing when the thing is on/working properly. I've never dealt with RTE regulators so all I know is what I've read.
Regardless what IVR it is, you need ground, then 12 volts in at switch on, and 5 volts out to one post of each thermal gauge.