87 F250 fuel electrical system.

[NicksFJ40]

Help any one, please.

Nick


87 fuel system electrical - Ford Truck Enthusiasts Forums

[WristPin]

Originally Posted by NicksFJ40

Carb not receiving fuel on start up, fuse # 15 & 18 are ok, I am not receiving power to the red/yellow wire at the fuel selector switch. Just before the switch at the wire plug there is a hot wire on the harness side but nothing on the switch side (blank), I ran a lead to the red/yellow wire from that hot wire and the truck starts and runs. The truck continues to run when the wire is removed. How does the red/yellow wire get its power? My Haynes book shows a "fuel pump relay" where is this located, could this be the problem or can it be my ignition switch?

Nick

the red and yellow wire is probly tied in with the ignition. check the contacts at the solenoid.
also, look for places where the wire may be broken or chaffed.

locate the said relay and test it. if it is a 4 oin bosch style relay,
86 is + from the switch, or ignition.
85 is ground
30 is bat +
87 is to the load, or in your case the fuel selector, or the fuel switch.

you need to locate a wire diagram. try autozone.com

a

[NicksFJ40]

Part of the problem is I dont know where the solinoid is located, I only have Haynes manual, and it doesnt show a location. One of the So Cal Club guys is going to fax me a wire diagram on Tuesday. Im guessing the power goes from the switch to the fuse box, to the solinoid and then to the fuel selector switch.

There are two solinoids on the left fender wall, one being the tow package, possibly the other is the fuel, it doesnt have a red/yellow wire, it could of changed color at the fire wall.

[WristPin]

no. there is not a fuel solenoid. it would be called a selector valve. and its not on the inner fender.

forget every thing you know.

there is a battery. connected to the solenoid. there are two wires coming off of that.
check make sure all those wires are tight.

this is how your electricity is going to flow in this order:

battery
solenoid
fuse panel
switch
relay
valve