I converted my car some time ago to 12 volts. I never could get the 6 volt system to be reliable enough and got tired of jumping it off and trickle charges. I changed the bulbs in the dash but did not mess with the gauges. The gas gauge wasn’t working because of a bad sending unit.
Well I got a new sending unit and wanted the original gauges to work. I bought some Runtz resistors to go from 12 to 6 volts. When I hooked up the resistor to the gas gauge it would not work. But when I put 12 volts straight to gauge it worked. Some said it would burn the gauge up others said it wouldn’t hurt it. I bought a set off of eBay just in case.
Well this morning the gas gauge wouldn’t read so I wired in the eBay gauges and a Runtz resistor and the gauge works fine.
I put in the correct sending unit for temperature I found out not any sending unit will work. I had 12 volts going to the gauge and it worked but it read close to 212 and my wife’s candy thermometer said 160. So I wired in a resistor and it reads close to 160 now.
I’m looking for a sending unit for oil pressure but since it’s on the same power wire as the gas one it’s on 6 volts now. I may have to separate them and have each gauge on a resistor. We will see.
So now I’ve got my speedometer working, my gas gauge, temp gauge and amp gauge working.
