Re: BigKev's 1937 115-C Convertible Coupe

Posted by TxGoat On 2023/4/26 20:55:06

It seems (per the diagram) that the gauge reading defaults to "Full" if there is an open between the dash unit and the tank unit. (Or anywhere else in the circuit)

If you're certain power is reaching the gauge from the ignition switch, I'd look for a poor connection or an intermittent tank to chassis ground. Another possibility is that the tank unit itself is not grounded to the tank. Adding a ground wire from the tank unit to the chassis might fix the problem. If the resistance element in the tank unit is broken or corroded, or if the moving contact brush is worn or corroded, it could make the gauge erratic. The gauge operates at very low current and voltage, and any poor connection anywhere in the loop will cause erratic action or no reading at all.