Fuel gauge and sending unit on my Dodge chassis Winnebago has died, I am going to buy a new auxillary gauge and sending unit to replace them, has anyone rewired in a new set-up like this to anything before and if so is there anything else I have to buy to make it work? I know the gauge and sender ohm's have to match but do you have to also buy some sort of resistor or regulator for the 12volt??