I have 1986 F 250 Extended Cab that has no power at the Pumps.
I can't seem to find any info about the wiring system in regards to the fuel system.
When I crank it over I have power at the fuel pump relay which is located by the master cylinder, I replaced the relay but still no power at the pump..


Any suggestions???

 

Here's a diagram. You can also do a search. This is a very very common problem with the 460 equipped trucks. I bet that's the engine you have correct?

 

Hey thanks Franklin 2:

After checking the wiring diagram I found that there is a Sensor or switch on the back of the intake manifold just below the oil pressure switch that has two wires connected to it that when I jump that connector he fuel pumps work great.

What is that sensor or switch called?

 

If I am correct it is a low oil pressure shut off switch. When the truck experiences low oil pressure, the oil pressure switch shuts the fuel off thus attempting to save the motor. I am dealing with similar fuel issues on my 84 F250.

Fuel pump cutoff relay. Mine is jumpered with a piece of wire and was when I got it.

EDIT:Added photo...

 

The oil pressure switch(shown in the diagram) is not to protect the engine. It's there in case you are in a accident, get knocked out and leave the key on, and a fuel line is cut. It keeps the electric fuel pump from emptying the fuel tank all over the accident scene.

 

Ok my local Napa does not have a replacement part for this! How do I fix this issue other then jump the wire?
Where can I find the replacement part?

 

Go to the parts store and see if a d1811 switch for a GM will work. Just tell them d1811 at advance auto. I think this is the GM version of the same thing, but I am not positive. If I were in this situation, I would buy it, and then hook it to my air compressor, and then slowly start turning up the air pressure while I had a meter on the two terminals of the switch. The two terminals should short together at round 5 psi and above if it's the correct switch. The original Ford plug may not plug onto this switch though, but the function should be the same if it passes the above test.

 

Archion actually found a replacement either Ford or aftermarket for it. BTW Franklin, mine does not have a tank selector relay, just the fuel pump relay.

 

hello i have a 1986 F-150 4X4 auto trans the fuel pump will not power up the only thing i did was replace the 305 engine with a 351W the fuel pump did work before the engine change when i turn the key i would hear the pump prower up can i use the above wiring diagram for my truck?? can you tell me where the fuel pump relay is i do have some repair books BUT they suck when i comes to wiring. thank you =^..^=

 

I assume you replaced the 302 with a 351W. Is the 351W an EFI engine? If not you are going to have all sorts of fun. The 302 EFI system had either 2 or 3 pumps depending on how many tanks. The carbureted 351HO and 460 engines may have had the hot fuel handling package which used very low pressure in-tank pumps.

 

Wrong thread, different engine, different fuel system, different wiring, different situation. I would start a new thread, look in the upper left corner of the forum page. Add more info like the other poster was asking about in the above post. Don't worry, we are here to help, we just need to get your problem in a different conversation that applies to your truck.

 

Yes the 351W is an EFI engine I have two fuel tank so i will have three fuel pumps right?? =^..^=