need help with fuel sender

[93PONY]

just like the title says. my factory gauge will not read accurate because the previous owner put white face gauges in and put all the needles on wrong. so im replacing with aftermarket stuff. well my fuel gauge is reading backwards, how can i fix this without spending alot of cash. i hooked it up to the factory wires at the fuel sender so i dont understand why it is doing this. it is a sunpro electric fuel gauge if this helps any.

 

[bullitstang1313]

What is the part number of the sunpro fuel gauge. I know that the sunpro fuel level sender is opposite of the stock fuel level sender. For the sunpro 240 ohms of resistance is empty and 33 ohms is full but for stock 25 ohms or so is empty and 200 or so is full. The gauge itself might be set up for the sunpro fuel level sender. Gauge CP7950 requires sender CP7583.

 

[Maryland Stang]

I remember reading about this but I don't remember the details. Some sending units increase ohms as the fuel level goes down and some decrease ohms as the level goes down. Your gauge is the opposite of the sending unit. There is a sending unit from an earlier Ford that will fit your tank that works the opposite of the Mustang unit. The detail I don't remember is which Ford it was.