Fuel gauge

[Steve]

My M37 was changed to a 12v and the wrong fuel tank and sending unit (12v) before I purchased. I have just installed an M37 tank with the correct fuel sending unit (24v). What do I have to do to get the fuel sending unit to read with my current 12v system?

thanks

Steve

[Matthew Ziegler]

sending unit

A sending unit is a simple rheostat, same thing you dim your lights with. use a 12 volt battery and a ohm meter to see how the stock sending unit reacts to 12 volts you might have to only buy a 12 volt gas gauge, if not see if one for a later 12 volt civillian Dodge will match up. You might end up drilling a couple of 1/8 holes in the tank and making a gasket at the very worst.

[Kaiser2boy]

A sending unit is a simple rheostat, same thing you dim your lights with. use a 12 volt battery and a ohm meter to see how the stock sending unit reacts to 12 volts you might have to only buy a 12 volt gas gauge, if not see if one for a later 12 volt civillian Dodge will match up. You might end up drilling a couple of 1/8 holes in the tank and making a gasket at the very worst.

Question? Did you hook it up? Did the guage pin hard over to full? Did the needle only go half way?
Is the tank full?
If it pinned over hard placing a wire wound resistor of the same resistance as the guage should bring the guage into a usable range.
If the needle only went half way on a full tank adding a resistor in series will only reduce the voltage to the guage and it will show less . You would need to parallel a resistor to the sending unit and that will not be a fuctional answer because it will cut off the lower end of the sending units resistance and give you a false low end reading , not good.

[Steve]

Thanks all. I have purchased a SW guage that should work. I will post how it works out.