Posted by David Sherman on Friday, October 27, 2006 at 8:54PM :
In Reply to: 12 volt with 24volt? posted by perry boquel on Friday, October 27, 2006 at 7:28PM :
Fuel gage accuracy is independent of battery voltage, but I'd be concerned about burning out the sender or the gage. A simple voltage-dropping resistor would probably work. If it was mine, I'd just stick a big rheostat in series with the gage/sender and adjust it till I got about 12 volts at the gage, then measure the rheostat resistance, calculate the power (~200/R watts) and pick a suitable fixed resistor that was close to that value. I have a large accumulation of rheostats and resistors, though. My M37 is 12V and has a civilian gage and sender so I can't measure it for you. Maybe somebody's already done that and can tell us the correct value for the dropping resistor. If so, I'll see if I have one and send it to you. If you're keeping the 24 volt military gage with a 12 volt civilian sender, I don't know what will happen, but it probably won't work.