TBI Dual tank wiring

[Wes]

Veh: 83 K10
Engine: 350 TBI conversion, new dual tanks, dual tank harness from EFI donor truck, in tank 87 pumps.

Issue: Circuit 120 - powering the pumps correctly.

Will someone check my logic? Have two wires coming up along frame rail, to engine cab. Tan-White (Circuit 120) - this one connects at the cab-switch?

The pink wire is the fuel gauge line, will connect it somewhere behind the cluster.

Do I need to rewire the cab tank selector switch to handle circuit 120 correctly?

 

[Dan Brown]

I'm doing the same thing on a 74 K10, and here's what I did. I was going to use a single higher pressure pump mounted on the frame, but then read that it's better to put the pump in the tank so the gas can cool it. I took two new pick up/sender units and spliced a pump onto each one. The way you need to control it, is you need to have a switch that will activate the valve to switch tanks, you'll need to switch the sending unit wire to the gage that reads the tank you will use, and you'll need to switch the pump to the tank you want to use. You can find toggle switches that will do all three operations with one toggle. I bought a 4 pole double throw switch from Amazon, but you really only need a three pole double throw. 12 volts comes into the switch and is jumped to two more terminals. All operations for one tank, left or right are wired to the other terminal banks, then use the other terminal bank for the other tank. Kind of hard to explain in writhing, but talk to someone who knows switches, and they can show you. I've got mine wired a when I put 12 volts to the switch, it works. Toggle in one direction, and all operations work for one tank, then toggle to the other direction and the other tank works. You only need to put 12 volts on the valve, as it is open to one tank with no voltage on it, and opens the other tank when you put 12 volts to it. Good luck.