Awhile back I upgraded my 1947 1st COE to a 12 volt system. I bought the appropriate Runtz reducers for the fuel and temperature gauge. Both gauges worked fine on the 6 volt system. The fuel gauge works fine on the 12 volt system with the voltage reducer. I fiddled and fiddled with trying to get the temp gauge to work and under no way could I get any reading, period.

I swapped out for the Chevrolet type of gauge with the capilary tube and never looked back.

Yesterday I pulled the dash out for a clean up and started wondering about the temp gauge again. Why would it not work with the Runtz reducer? Yet it still works if 6 volts is applied? I have a pair of GMC electric temp gauges and a few 6 volt senders for them.

Is it possible that the gauge could work without the reducer? I really dont want to fry the gauge attempting something that may not work.

Also, the Chevrolet gauge is barely long enough to work which is probably what started me thinking about the old GMC electrical gauge.

Any insight is appreciated!

Thanks, Jeff

My 1953 Chevrolet
1947.1 Gallery
1972 C-10 1/2 Ton & 1972 C-30 1 Ton