1987 Chevy Truck Wiring Diagram For Gas Tanks Jul 31, 2017Searching for information regarding 1987 Chevy Truck Wiring Diagram For Gas Tanks? you are right here. You could be a professional who intends to seek references or solve existing problems. Or you are a pupil, or maybe even you who just wish to know about 1987 Chevy Truck Wiring Diagram For Gas Tanks. Repair Guides5/5 Wiring diaghram for fuel pump on 87 chevy p/u v8 dual tank Apr 11, 2007Wiring diaghram for fuel pump on 87 chevy p/u v8 dual tank - Answered by a verified Auto Mechanic I have a 1989 f150 ford truck. it has dual tanks. I have 2 problems. first i couldnt get the fuel pumps to switch from the back to the front. 1987 Chevrolet 20 series van 305 Already Tried:Here ya go,What do you mean? Do you want to change it to a one tank system?Your also going to have to reroute the fuel lines to make this work. You have to bypass the selector valve and connect the left tank directly the the feed hose. Go to the tank switch and cut the tan wire and the tan/white wire and connect them together. Now go to the tank selector valve and cut the pink and pink/white wires and connect them together. That should do it.The answer is still the same. You just have to go back and search for where the wire is cut off. You can see in the diagram where these wires are coming from.No, the red test lead is never hot. What it's for is to apply power to it and it should power the pump when the relay is OFF. Once the relay energizes, that lead is isolated and not connected to anything. You should have power on the orange all the time at the relay. the Dk green and white only powers for the first 2 seconds of key on and when the car is cranking or running. This truck is also wired for a redundent power supply for the fuel pumop through the oil pressure switch. It will power the pump aftyer oil pressure builds even without a relay.