ALT/GAS Switch, ALT/GAS Switch Light

The ALT/GAS switch sends a signal to compuvalve requesting ALT fuel mode, when placed in the ALT position. If compuvalve does not receive a signal, bi-fuel system defaults to gasoline mode. The ALT/GAS switch light is incorporated in the ALT/GAS switch. ALT/GAS switch light is controlled by compuvalve and is illuminated when operating in ALT mode. If an emission-related Diagnostic Trouble Code (DTC) is recorded, ALT/GAS switch light will begin flashing. If a communication fault exists, ALT/GAS switch light will flash steadily. Once ignition switch is turned to On position, ALT/GAS switch will not change fuel operating mode.

Dual tank configurations used on F-Super Duty 350 (if equipped), utilize an ALT/GAS switch with 3 positions for selecting each of the fuel tanks individually (Gasoline, LPG tank No. 1 or LPG tank No. 2). The 3 position ALT/GAS switch has 2 separate ALT lights that will illuminate to indicate which LPG tank is being used. Bi-fuel system operation with 3 position switch is identical to 2 position switch.