My 90 F250 with 7.5l cranks but won't start. I replaced the coil, plugs, wires fuel filter, cap and rotor. After replacing the left side bank of plugs, the truck would crank but not run. I did some research and jumped the fuel pump port to ground on the EEC test plug and the truck still wouldn't run. I replaced the computer and still no love. I jumped the fuel pump port again and the truck fired up and ran 3 days, no problem. Then it died again and I'm back to the crank won't start condition. Here's the bad news.
Yellow wire to the fuel pump relay - 12v
Red with green stripe to fuel pump relay - 12v
Solid red to fuel pump relay - 12v
Black wire to fuel pump relay - 0v
Green with brown stripe to impact switch - 6.0 - 6.5v
Pink with black stripe at impact switch - 0v (tried with switch open and reset or closed)
Center wires coming into tank selector switch - 6 - 8v
Wires going out of TSS - 6 - 8v (works both ways)
I checked continuity at the fuel pump relay (new) check out good
I checked continuity at the impact switch, checked out good
I checked continuity at the TSS, checked out good in both positions.
I checked continuity of the wire from the fuel tank to the plug on the fender well, checked out good. Then the wire disappears into a giant loom, but I have continuity from the red/green strip wire and the solid red wire at the fuel pump relay to the red wire that goes all the way to the pump. Continuity but NO VOLTAGE. Can anyone help me determine what's going on with this mess?

Thanks.

 

In a possibly related thread, there are two of what appear to be fuel pump relays on the fender well. One has a green connector, the other has a brown connector and the pins of the relays are identical.

 

There is not a black wire or a Red with green stripe wire at the fuel pump relay.
Did you mean Tan with a light green stripe as opposed to Red with green stripe wire at the fuel pump relay?
Did you mean a Brown wire opposed to a black wire at the fuel pump relay?

It sounds like the Tan with a light green stripe is not being grounded by the PCM Computer.


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Subford - many props, you seem to be a guy who knows Fords inside and out. Seriously, no brown wire, no tan with light green stripe. How do you post pictures? I'd like to show you the two relay connections on the driver's fender well.

 

Also, at the front tank, I have four wires going to the top of the tank. Red, solid orange, blue with yellow stripe and black. Neither pump works when I turn the key on and the truck won't run with either tank selected.

 

You can email the photos to me at:
subford@gmail.com

 

Hi. Mr.subford I am having the same weird problem I've posted a video on YouTube of it. Is it alright if I email you to see if I can fix my dilemma.

 

Yes it is OK to email me.

 

So what about the forum? It stops here and continues privately? Why are all the pics, drawings and diagrams originally attached to the posts removed and no longer accessible along with the related post and/or content it was intended for?

 

There were no diagrams or pics in the original posts, looks like this one went offline.

Best advice is to start your own thread describing the issue(s) you are trying to resolve.