Truck won't start....

[stamp11127]

Has a portion of the wiring diagram, post 12.

https://www.expeditionforum.com/threads/2003-5-4-eb-fuel-pump-relay.33325/

 

[Hamfisted]

Yes, the green/yellow wire is 12v INPUT to the inertia switch and the pink/black wire is 12v feed TO the fuel pump. If you're not getting 12v at the green/yellow wire start working back to the fuse box. Is it the original fuse box ? If so it's highly suspect. The replacement fuse box has heavier duty fuel pump relay installed. But save the fuel pump you ordered, because the fuel pressure check valve will fail shortly and you'll have to replace the fuel pump anyway.

 

[johnboneske]

At the green/yellow wire on the inertia switch I have 12 volts when I turn the key. So, it has to be the pump, right? I didn't check the output of the inertia switch though, just thought of it now, guess I should check that the switch is good.

 

[Hamfisted]

Do you have a fuel pressure gauge to check the fuel pressure at the fuel rail ? If you're getting 12v at the pink/black wire off the inertia switch then I trust that you would be getting it at the pump. If you have 12v on the pink/black wire but no fuel pressure at the fuel rail schrader valve, then I would start syphoning gas out of the tank to get it as light as possible, 'cause that's your next job.

 

[johnboneske]

I have tried to purge fuel at the rail, I don't have a fuel pressure gauge to attach, but have removed the Schrader valve and don't get any fuel out of the port. I will let you know what I find out

 

[TobyU]

Get underneath it and bang on the bottom of the gas tank with the palm of your hand over and over as someone turns key on and off for 2 secs at a time to prime.
I have had more than one car do this and got it to start this way.
Had an excursion that would not start when cold after sitting all night.
Once it started it was fine for the day. I learned to do a lot of key primes and it would start but one time had to put a torpedo heater under it and block off sides around rear to warm it up. Started up quicker that way.
Then one night after a harder start but it had been fine all day, I turned it off as gas station on way home and it wouldn't restart. The third hit on the tank got it spinning and it was fine home. I replaced it after that.
93.00 for lifetime Delphi at Autozone about 3-4 years ago.

 

[1955moose]

Try Toby's hail Mary, I've done that with starters for 45 years. Fuel pumps always seem to take a dirt nap right after throwing in 20-25 gallons. Short of dropping tank, and checking for power at pump itself, you've done your due diligence. What year John is your SUV? I read all the posts, but didn't see a year. On my 2000, I had the relay go out about 10 months back. Mine had removeable relays, so I was able to swap another out. Yours is beyond 2003 if memory serves, but you've done all the bypasses, so looks like it's towing time. Don't think the campground folks will be happy with that type of repair at their facility. Keep us posted if and when your up and running.

Sent from my N9131 using Tapatalk

 

[johnboneske]

My Expedition is home! I had it towed home, cost $120... I got the new pump and plan on dropping the tank tomorrow. After that a For Sale sign goes on it!

 

[johnboneske]

Oh, I am taking off my tow mirrors and am home sell them. Know anyone who wants a set, let me know.

 

[riphip]

Post #5 video: around 1:04 into it shows the bad spot on the circuit board. Mine did this and I had to replace the relay. Desolder & solder in new one.