Inliners International Forums General Discussion Electrical 12 Volt conversion

I recently purchased a 1954 GMC 1/2-ton PU and apparently this truck was converted to a 12 volt generator system, but I am not sure if it was done entirely correct. The part I am unsure about is whether they put voltage reducers in for the all the gauges and the for the heavy duty accessories like the heater. Is there a way to tell if there is a voltage reducer installed and where would it likely be installed. My gas gauge does not currently work and I was wondering if they broke this gauge by not installing a voltage reducer when they converted it to 12 volts. Any help on this issue would be much appreciated. Thanks.

Hi I had a simular problem back in the mid 80's before I knew better. I converted my 53 club coupe to 12 volt and burned the gas gage out. All it takes is a small resistor I don't remember the resistance if I find the extra ones I have I will send you the numbers. The oil and the temp gages are not affected and the amp gage worked on mine did not affect it. the resistor goes right to the gas gage itself, or to the hot wire so that it wont burn the gage out. It would be simular to the heater motor. If no resistance to the heater motor then the motor will burn out quick,be careful. check it with a 6 volt battery first and if it still works put a resistor between the fuse and the motor. I believe that you need a resistor in your line to your points to keep them from burning out, as well. My 53 ran great until one day I was at a stop light and it would not start after it dyed. It was the points had burned closed. Live and learn right. I also have a 54 GMC but it is in boxes and I dont know if all the gages are electrical or not if so I am sure you need resistance. I hope this helps some good luck.

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Look on page 360 of "Speedway's" new catalog-- the"Runtz" advertized may help you out with gauges(only$17.95) and the 12volt conversion guide may also be helpful---Paulweldit

To cujo I have a foot type 12 volt starter and generator w/regulator yours for the cost of shipping from SoCal. Chuck.

When I rebuilt a 53 Chev wagon I took the parts from a 55 Chev for the swap (Starter, Generator, Coil, bulbs, Heater Fan motor, etc). Many folks told me to just leave the 6 volt starter on but it burns out after a while and you need to get a new one. I seem to remember someone saying that the tank send unit on these acts as a variable resistor to give you the action on the guage and when I changed over to 12v I dropped a 12v send unit in and seemed to have ok action on the guage. Perhaps the car unit is designed with a different resistance than the truck to begin with? I remember being amazed that I didn't have to put in a step down resistor. I sold the car a couple years later, so don't have it handy to check on longevity of this set up. All other guages functioned as normal. Hope this is of some use.