The GM Fuel Gauge Mystery 1965 & Newer

Diagnosing a problem with a GM fuel gauge or sending unit can be very frustrating and part of this frustration comes from not knowing the theory behind what makes that little needle swing back and forth in your dash or console. And, there are a lot of enthusiasts out there who are deathly afraid of the “wiring monster” that lives behind the dash. If provoked, the monster will jump out and bite them. The fuel gauge is not one to be afraid of and most problems can be solved with the proper ammunition! We have received many calls on fuel gauge issues we thought it would be a good idea to provide our readers with the basic knowledge of the fuel level circuit and testing procedures.