Most cars, including vintage Mustangs, have a fuel-tank sending unit that conveys to the fuel gauge the amount of gasoline in the tank. Sometimes they quit working and need replacement. No need to worry though, as the R&R procedure on a vintage Mustang is quite easy.
The following photos and captions show exactly how we replaced the sending unit in our '69 Mustang project car. Our friends at Mustang Country International had our car up on the shop hoist, the fuel tank drained of about six gallons of gas, and the new sending unit installed in our car in about a half hour. We acquired a sending unit from Mustangs Plus, a Northern California vintage-Mustang parts house whose print catalog and Web site offer just about any part you can think of for '65-'73 Mustangs, as well as a few late-model bits, too.
While the sending unit in our car still worked fine, we wanted to show you how to do this basic but still fundamentally important repair.