They tell me no. Because the voltage changes as the fuel level changes, The balast resistor needs the same constant draw to do it's job correctly. You need a runtz. I think that was the name.
Ballast won't work with such a very low draw. Those resistors drop the volts depending on the load on them. There would be almost no noticable drop in volts if you hooked it to a gauge.
Find a cell phone car charger, read the fine print on it. Most drop 12 volts to 6 volts. Gut the plastic and use the electrics inside to power your gas gauge. I have done this and it works perfect. Garage sales and flee markets have them for a buck or two.
What vehicle are you working with? Resistors are not a good way to drop the voltage, due to variance in draw inherent to the action of the sending unit (as stated above) and construction of various gauge designs. You need a solid state, constant voltage regulator. www.morrisgauge.com
From what I've read a fuel gauge is nothing more than an ohm meter. I wired up my fuel gauge in my 41' Ford convert with no voltage drop device at all, about forty years ago and it works fine.
When I converted my Crosley to 12v the "kit" included a Runtz vlotage dropper, works good..Small but not cheap, around $16....
I agree with 550Coupe, I know quite a few guys on a truck forum that use 12V on their 6V gauges with no problems at all. They draw very little current, just a few milliamps so doubling the voltage just ups the current a few more milliamps. Some of these guys have been running this way for 20 years or more.
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