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Arench
Arench, Master Technician
Category: Ford
Satisfied Customers: 1490
Experience:  30-years experience auto and truck repair.
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1990 Ford F250: the fuel pump relay, and the fuel pump..front tank

Customer Question

I have a 1990 Ford F250. I have changed the tank transfer switch, the fuel pump relay, and the fuel pump in the front tank and still have no power to the front pump. Can you help?
Submitted: 8 years ago.
Category: Ford
Expert:  Arench replied 8 years ago.
Greetings from Mikey at Just Answer.

Did you press the button on the fuel pump cut off switch? The switch is a black box with a white or red button on it. Its located under the dash usually in the left kick panel near the parking brake or on the firewall under the dash above the brake pedal. Check for power going in and out of the fuel pump shut off switch while cranking the engine. Should have 12v power at both wires during cranking. Report your findings here.
Customer: replied 8 years ago.

Dear XXXXXy,

 

Thank you for the tip on the fuel pump shut off switch, However there is no power in or out of the switch. It was located next to the kick panel just like you said but my problem is still there. Any further advise would be greatly appreciated by this back yard mechanic.

 

Thank you,

Dave

Expert:  Arench replied 8 years ago.
Just to be sure, there was no power at the shut off switch on either wire while cranking?

Both fuel pumps don't work?

Check for battery voltage at al times at the yellow wire on the fuel pump relay.

Hold the relay and have someone turn the key on. Does the relay click?


Customer: replied 8 years ago.

Dear XXXXXy,

 

You are correct, there is no power to either pump. I just checked for a clicking in the relay and there is none. So seems to be a power problem?? I was driving the truck home and it just stopped running apparently losing power to the fuel pump when this all began. Thank you for any further imput.

 

Perplexed,

 

Dave

Expert:  Arench replied 8 years ago.
Check for battery voltage at all times on the yellow wire at the fuel pump relay.
Customer: replied 8 years ago.

Mikey,

 

I am locating a voltage tester and when I get the reading on the relay I will get back to you, but it probably won't be until tomorrow evening. Enjoy your afternoon.

 

Dave

Expert:  Arench replied 8 years ago.
Thanks Dave.

A test light will work just as well. Pick up the EEC relay while your are out. Laughing

I'm watchin a little football sittin by the woodstove.
Customer: replied 8 years ago.

Mikey,

 

Dont know how you stay awake in the heat from your wood stove, maybe you didn't!

 

Well, I replaced the EEC Relay and put a test light on the yellow wire at the fuel pump relay while cranking and there is no power. Hope you can steer me to a solution.

 

Thanks,

 

Dave

Expert:  Arench replied 8 years ago.
lots of coffee!

Oh my thats the battery power wire for the fuel pump. You are going to have to examine the fuel links at the battery cable side of the starter relay. The yellow wire comes out of the harness by the starter relay ant attaches with a blur fuse link to the battery side of the starter relay. Yank on the yellow wire and see if it pulls apart, repair as needed to restore power to the yellow wire at the fuel and EEC relay.
Customer: replied 8 years ago.

Dear XXXXXy,

 

This feels like it could be the problem, however it will take me and evening or so with my schedule to determine if this is it. Thank you for sticking with me and I will let you know what I find. This has been a reliable old truck and thank you for trying to help me keep it going.

 

Talk to you soon.

 

Dave

 

 

Expert:  Arench replied 8 years ago.
No trouble Dave. Yes, I think you have discovered the problem. There is a bad connection at the starter relay battery side or a burnt fusible link. Either that or something is eating the wire harness Laughing Yummy!
Customer: replied 8 years ago.

Mikey,

I apologize for taking so long to get back to you. Wednesday evening I did discovered a corroded end on the fused link. I repaired the end and now have power at the fuel pump relay yellow wire. However, now I do not have power at the power at the fuel pump shut off switch. Can I jump the two wires at the shut off switch to see if my fuel pump runs? Could one problem have caused another?

Frustrated,

Dave

Expert:  Arench replied 8 years ago.
You have to be cranking it when you check it and have everything plugged in. Does the relay click now when you first put the key on?
Customer: replied 8 years ago.

Mikey if you are still there, I just cranked the engine over and there is no clicking sound at the fuel pump relay, so am I back to square one?

 

Dave

Expert:  Arench replied 8 years ago.
Make sure the yellow wire at the eec relay has power too.
Customer: replied 8 years ago.
Should the EEC relay also make a clicking sound? If so, it does not.
Expert:  Arench replied 8 years ago.
It comes on with the key but stays on. The yellow wire at the eec relay should have power at all times.
Customer: replied 8 years ago.

Going to go watch a movie for now. I'll do a little more investigation tomorrow. Thanks for your time. Talk to you tomorrow.

 

Dave

Expert:  Arench replied 8 years ago.
Ok Dave. Its a different fuse link that powers the yellow wire to the EEC relay, at the same spot.
Customer: replied 8 years ago.

Mikey,

 

I have been suffering from a poor ground on my test light. Today I ran a good solid ground wire for my test light and have discovered the following. With the ignition in the on position and while cranking I have power to the fuel pump relay yellow wire. With the ignition in the on position and while cranking I do not have power on the EEC Relay yellow wire. Is this better or worse?

 

Thanks for your continued interest

 

Dave

Expert:  Arench replied 8 years ago.
The same. Back to the fuse link connections. There must be power to the yellow wire at the EEC relay at all times.
Customer: replied 8 years ago.
Where is the fuse link for the EEC relay?
Expert:  Arench replied 8 years ago.
Same spot as the one for the fuel pump relay that you repaired already.
Customer: replied 8 years ago.
Is there more than one fuse link or does the same fuse link supply power to both wires. My fuse link has 1 wire to the starter relay and 2 wires from the fuse link to the wiring harness.
Expert:  Arench replied 8 years ago.
There should be more than one fuse link attached to the battery side of the relay.
Customer: replied 8 years ago.

Mikey,

 

That will give me something to check out in the morning. I don't want to leave you hanging tonight. Have a good evening.

 

Dave

Expert:  Arench replied 8 years ago.
No problem Dave, I'm just watching football.
Arench and 8 other Ford Specialists are ready to help you
Customer: replied 8 years ago.

Dear XXXXXy,

 

You have been a trooper. I truely appreciate your efforts in resolving my fuel pump problem, however it has taken its toll on my patients. I had the local Ford garage come and get the truck today and if you like I can write you back what the mechanic discovers. Kudos to all professionals in your line of work trying to decipher problems such as mine. I have checked the accept box because I feel you have helped me as best you could under these circumstances. I hope your favorite team makes it to the Super Bowl and keep the wood stove stocked.

 

Sincerely,

Dave

Expert:  Arench replied 8 years ago.
Hi again Dave. Thanks very much. Well, the Steelers are still in the hunt so thats good. I hope they will find your problem quickly. Once they resolve the power issue to the PCM relay you will problaby be okay. I hope you will keep me informed.
Customer: replied 8 years ago.
Is there a way we could contact you directly through this site or are we at the mercy of whoever picks this up first? In case I have questions in the future.
Expert:  Arench replied 8 years ago.
You can request a particular expert by going to this question and clicking on my name. You will see a question ask box.

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