gauge frustration

I have a 1966 Barracuda. The voltage limiter in the temp gauge stopped working and burnt out some of my gauges. I purchased a used instrument cluster which the voltage limiter in the temp gauge also didn’t work. However, I took 3 AA batteries taped them together to get 5 volts and tested all the gauges. They all swept properly. I purchased an external limiter and installed on the outside of the cluster. I took the 12 volt feed to the temp gauge and spliced a terminal on the wire so it would plug into the voltage limiter. I then plugged the voltage limiter into the other terminal on the temp gauge. My temp gauge stays on cold. I test the senor wire for voltage and I am getting the proper swing about 0 to 6 volts on and off so I know the limiter is working properly. I ground the sensor wire and the gauge sweeps properly. I am on my 3rd sensor and cannot figure out why it is not working. Any help would be greatly appreciated.