Dual Tanks Switch Valve? - 73-87ChevyTrucks May 03, 2011unplug the wire on the valve (I'm assuming your valve has a single wire like mine) and put a voltmeter between the wire and a ground, then have the helper switch the switch. If it's like the one on my 78, you should have 12 volts when the switch is set to the left tank, and 0 volts when it is set to the right tank. Dual fuel tank selector - Chevy Message Forum Jan 31, 2011Do any of you guys have a good wiring diagram that you can copy and send me of this truck with dual tanks, I have purchased 2 books now and the wiring diagrams are junk, don't show much and I would like a more detailed look at the wiring system. thanks in advance for any help! So, in review, I had a problem with my '86 Chevy PU 350 e/w an Related searches for chevy dual tank wiring diagram chevy engine wiring diagramchevy wiring diagrams freewiring diagrams for chevy truckschevy wiring diagrams sitechevy van wiring diagramchevy engine wiring harness diagramchevy truck starter wiring diagramchevy schematic diagrams