I have a 2001 F250 V10. The truck will not start, no fuel. I started checking the power going to pump and I am finding I am only getting 6.9 volts to the dark green/yellow wire. I bench tested the relays under the hood and all have continuity. I am not sure if there are any other relays that can be checked. I am hoping someone can help me out.

Thanks
Mike

 

You do know, don't you, that the pump is only powered for around 2 seconds only when the key if first turned from OFF to RUN, until the engines starts?

Any reading made outside that window is irrelevant and prone to cause confusion.

 

And its been my experience that 9 times out of 10 a no start on our trucks ends up being the fuel pump..

 

project Thank you, I didn't know that about the pump. I was trying to advoid dropping the tank, But I guess i will have to.

Thank you both for your comments

 

Don't know if ford gas trucks are like ford cars, but my '04 crown vic has a fuel pump module that controls the power output to the inertia switch, if that is bad then you don't get full voltage.

 

An 01 Super Duty does not have the FPDM.

A fuel pump replacement may well be in your future, but your initial diagnostic method is invalid and would likely result in wasted time and effort. Doing the diagnostic PROPERLY will get you to your correct diagnosis quickly. If you have your battery power at the output of the inertia switch during the pump priming cycle, then you've eliminated everything except for the rear wiring harness and ground and the fuel pump.

 

I think you are on the right track. I just went through this on Thursday with my v10 superduty. drove home from work, it started running like a 4 cyl and then I shut it off and would not start again. I checked the fuse under the hood, good. and found the relay was working, I had good voltage to the inertia switch.


you should have battery voltage at the inertia switch when the relay is activated. Anything less than battery voltage usually indicates a problem with the relay or battery voltage in general. did you crank the car a lot trying to start it?


anyway, my relay for the fuel pump is up under the dash behind the radio area. its a pos to get to but you need to check it.


the system is simple (mine is a 2001) the ecm grounds the relay and also monitors the voltage output from the relay. the relay takes battery voltage and sends it to the inertia switch when activated, through the inertia swich and on to the pump. Mine ended up being a faulty pump. It was not that bad to change the pump but a final test is to crawl under the truck and find the B+ power wire to the pump itself and have some one turn on the key while you are testing voltage there. you should see battery voltage for a 2 sec period when the key is turned on. if you have no voltage or low voltage to pump you have other issues. if voltage is good, you need a pump.


BTW.... I pulled the bed off for the pump replacement, it is much easier providing the 6 bolts come out of the bed easily.

 

Thank You everyone, I finally had a chance to drop the tank and replaced the fuel pump. The truck runs beautiful again.
Thanks
Mike