Electronically controlled selective valve system for fuel level balancing and isolation of dual tank systems for motor vehicles

A mobile vehicle, comprising:

• a chassis comprised of frame members with an engine engaged for driving the vehicle;
• at least two fuel tanks, a first tank and a second tank, engaged to said chassis frame members;
• each said fuel tank have a fuel level sender;
• said fuel level senders electrically engaged to a vehicle electronic controller to provide fuel tank level indication to said electronic controller;
• a draw line from said first tank engaged to a first inlet to a draw control valve;
• a draw line from said second tank engaged to a second inlet to said draw control valve;
• an outlet from said draw control valve engaged to supply fuel to said engine;
• a common return line from said engine being engaged to an inlet of a return control valve;
• a first tank return line being engaged from a first outlet of said return control valve to said first tank;
• a second tank return line being engaged from a second outlet of said return control valve to said second tank;
• said electronic controller engaged to control said draw control valve and said return control valve such that when said first inlet of said draw control valve is open from said first tank and said return control valve is open to return fuel to said first tank, said second inlet of said draw control valve is closed from said second tank and said return control valve is closed to said second tank;
• said electronic controller engaged to control said draw control valve and said return control valve such that when said second inlet of said draw control valve is open from said second tank and said return control valve is open to return fuel to said second tank, said first inlet of said draw control valve is closed from said first tank and said return control valve is closed to said first tank;
• a selector switch with three positions, an AUTO, a first tank position, and a second tank position;
• said electronic controller programming comprising, when said selector switch is in AUTO, the steps of:
• initially aligning said draw control valve draw from said first tank;
• shifting said draw control valve to draw from said second tank when level in said first tank falls a specified differential tank volume below said level in said second tank;
• shifting said draw control valve to draw from said first tank when level in said second tank fails a specified differential tank volume below said level in said first tank;
• and
• repeating said steps of alternating drawing between tanks as volume falls to specified volumes below the other of said tanks;
• said electronic controller programming comprising, when said selector switch is in a first tank position, the steps of:
• opening said draw control valve to draw from said first tank and opening said draw return valve to allow fuel to return to said first tank;
• and
• isolating said second tank by closing said draw and return control valves to said second tank;
• said electronic controller programming comprising, when said selector switch is in a second tank position, the steps of:
• opening said draw control valve to draw from said second tank and opening said draw return valve to allow fuel to return to said second tank;
• isolating said first tank by closing said draw and return control valves to first second tank.