hi guys, been a while since i posted but this forum has been a great help in my build. Refresher, i have 55 ford 2dr customline with 351c. now i am running a 12v temp sending unit and i purchased 2 12v temp gauges from mac's old car part place and they were for a 56 t-bird and are 12v gauges. i have an e-z wiring kit in the car. i started the car up the gauge was the cold side and let it run for awhile, the gauge's needle started moving up to about half way and i took heat gun and where sending unit was it showed around 180 degrees, after a few minutes it went way over to right to overheating side of gauge and motor temp was still 180. shut off and gauge stayed on hot side after it cooled down and gauge stunk like burnt and i took it out and tested on battery and the thing did not move. now that was the 2nd gauge i burnt out. i called e-z wiring and they said i had it hooked up right with power in to one side of gauge and wire from other terminal to sending unit. what sucks is that these gauges from mac's were $90 apiece and ez wiring said it might be the gauges but mac's says no it isn't and they don't know what caused it. ok i have to edit to add i have a voltage reducer for the gas gauge and spliced into power wire to it so i have 12v coming to temp gauge and still have 6v to gas gauge. i don't know if this screws stuff up or not.
Fords (and others) have a resistor under dash that powers gauges with 6 volts. If you are supplying 12 volts to your gauge, you are letting the smoke out with twice the value. (voltage)
mike, i bypassed the voltage reducer to have 12v go right to temp gauge, i have some pics i will add to my post when download them.
What Mike is saying, even though the TBird may have been 12 volts, it still had a reducer for the gauges, Ford still used a reducer into the late 70's that I know of, same with Dodge.
so if i hook the reducer up to another gauge that is 12v tbird, it should work, will i be better off then to switch sending unit on motor to a 6v one also or just leave the 12v one on. thanks
Sending units are just variable resistors, not voltage dependent, yes, the gauge needs to be fed from the reducer....again, the TBird had a reducer behind the instrument panel if it was a 12 volt car
ok, would i be able to put back in a 6v temp gauge even tho the sending unit is 12v, would the ohms be different as i have read here some place before or will it work with the reducer no matter what. thanks.
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