Thanks for the kind words. There were some years when GMC used an electric temperature gauge, I believe it was. That is why I used the word "correct" describing the harness because there were differences between GMC and Chevy. On the Chevs, the two components to worry about with the 12v conversion would be the blower motor and the gas gauge. The starter should work fine on 12 and of course all the bulbs get changed.
