1970 Mach 1 Gauge Issue - Voltage Regulator

I recently had my instrument panel and gauges refurbished and a couple of things that were done are to replace the voltage regulator and printed circuit board.
Now when I plugged in the instrument panel, the gauges begin to come to life, but before the needle on the fuel gauge gets to 1/4 full the needle goes back to zero. This occurs with all the gauges.
I have been told the problem is the new solid state voltage regulator. Apparently the new SS VR's require a full 12 volts and the power to the panel is limited to something less than 12V.
Does anyone know of a fix for this issue?
Thanks, Stan

My problem was resolved by using an old (non-solid state) functioning IVR.
The alternate fix was to tie into a full 12V supply, by-passing the resistor wire that normally feeds the IVR.
I hope this helps someone.