Crank no start issue

1990 FORD F-250
180,000 MILES • 7.5L • V8 • 4WD • AUTOMATIC
Avatar
COLBYC1564
  • MEMBER
  • 3 POSTS
So, I drove the truck to work and home and ran fine, now I have a crank no start. I have power to the fuel pump relay and inertia switch wand out of both but no power to the fuel pump itself and can't find a wiring diagram to see if it has a fusible link or what.
May 27, 2022 at 8:14 PM
Advertisement
Avatar
SQM
  • CERTIFIED EXPERT
  • 6,383 POSTS
Hello,

So, if the inertia switch is tripped you will not get power to the pump.
And yes, there is a fusible link.

There also could be a short in the wiring causing no power to the pump.

https://www.2carpros.com/articles/how-to-check-wiring

I have attached the wiring schematics below for your reference.

Let me know of any questions.
Thank you.
May 27, 2022 at 8:48 PM
Avatar
CARADIODOC
  • CERTIFIED EXPERT
  • 34,308 POSTS
Here's everything for "Engine Controls". If you find these hard to read, let me know which parts you need, and I'll cut them up so they can be expanded.

There is a fuse link wire shown at the top left of the first diagram.
May 27, 2022 at 9:11 PM
Advertisement
Avatar
COLBYC1564
  • MEMBER
  • 3 POSTS
They all have power other than that one.
May 29, 2022 at 9:06 AM
Avatar
CARADIODOC
  • CERTIFIED EXPERT
  • 34,308 POSTS
Test fuse links by tugging gently on them. If it is good, it will act like a wire. If it's burned open, it will act like a rubber band.
May 29, 2022 at 11:07 AM
Avatar
COLBYC1564
  • MEMBER
  • 3 POSTS
I power probed them all. They all had power on the other side of link. I went ahead and replaced three of them just to be safe but still no power. Also replaced the fuel pump relay and have tested the wires at the tank the only one that has power is the big orange solid orange wire none of the other wires have power with key on and eec jumped with a wire.
May 29, 2022 at 2:17 PM
Avatar
KASEKENNY
  • CERTIFIED EXPERT
  • 18,907 POSTS
Just seeing that you have not had a reply in a few days, so I am wondering if this is still an issue.

If it is based on the fact that you have voltage on the orange wire but nothing else means we may have a greater wiring issue.

According to the wiring diagram the orange wire is on the ground side of the pump.

So, you should have a red wire coming into the pump as well. This should have 12 volts on with the key in the on position.

If you do not, then we are going to have to dig deeper into the wiring.

I would suggest we disconnect the wiring from the pump and then just run a jumper wire directly from the battery and then run your own ground.

This will confirm we have a wiring issue, and we can narrow it down as to where the issue is.
Jun 2, 2022 at 9:54 AM