How to: - Ford Explorer Fuel Pump Electrical Procedure | Page 2 | Ford Explorer Forums - Serious Explorations

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How to: Ford Explorer Fuel Pump Electrical Procedure

Prefix for threads which are instructional.
Thank you for your reply. I will have to recheck these in the morning as it is to dark for me to see . Vision ant what it use to be!
Thank you for your time .

The new fuel pump I put in runs when I hook my charger to the 2 wires/ pins.

They did away with the pin/blk combo and only have a red wire and a black wire so that is what I hooked up to and it runs.
On the non-pump side I had my meter on ohms and I got 000.4 when I read the meter hooked to the chassie ground and I took that ground strap off and cleand it up and reinstalled it . It was very dirty
 



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do pins match?

The new fuel pump I put in runs when I hook my charger to the 2 wires they did away with the pin/blk combo and olnlhave a red wire and a black wire so that is what I hooked up to and it runs.
On the non-pump side I had my meter on ohms and I got 000.4 when I read the meter hooke to the chassie

It sounds like you purchased an aftermarket complete fuel pump assembly instead of just the pump. Your results sound normal. Make sure the pins in the connector on your fuel pump assembly line up with the pins on the mating connector and make good contact.
 






Yes I bought the whole thing . and th pins are the same and all that looks good. The couple of seconds I ran the fuel pump . I went to the schreder valve at the engine and I have fuel! I found 2 ground straps from the chasse to the body and one was shot so I replace it and the other I was able to clean up. I also found a ground the the passinger side fire wall with some boxes grounded at it and I took it apart and cleand it. I was just checking the tnertia switch again and when I turn the key on I cant read any power to it? Do you know where the power comes from to the switch?
 












I checked fuse 9 BJB it is good. Is the C 147 going to the PCM ? I also took out the pump relay 48 and put a jumper on 3 & 5 contact as I have read earlier , still nothing .
I dont know what happend befor I replaced the fuel pump and I hit the tank with a rubber hammer and the pump came on . That's what led me to belive the pump was bad in the first place.
Dont know how much more I can do on this myself and the couple of half machanics I asked in my area dont know what is going on with the electrical side of this.
May have to put it all back together and get it towed someplace.
Thank you for your help
 






lowered the tank too far?

When you lowered the tank to replace the fuel pump was a strain placed on the fuel pump wiring harness? The black wire is spliced near the frame in the vicinity of the fuel tank. If you strained the splice it may have broken. You said you have battery voltage at the connector that mates with the fuel pump harness. You also said there was almost a short from the black wire to ground. But then you said there was no battery voltage to the inertia switch. I suggest leaving the jumper in the fuel pump relay and then grounding the black wire that connects to the fuel pump and see if it runs.

Edit: The connector to the fuel pump harness must be connected when you ground the black wire.
 






Yep they have this working now. I was just checking to see if I could reply and all that ( JAVA) stuff is gone.
 






Would someone do me a favor and draw a diagram to show me or point out on "Step 3" where relay contacts "3 and 5" are located, i tried to use common sense and jumped where it was marked "30" being 3 I thought, to 85 which I thought would be 5, I burnt my fingers and got a spark, not good. So if someone would draw one up or use a photo I sure could use it ty.

Edit:
I guess I should add it is for a 1999 Ford Explorer 5.0l V8 Automatic AWD XLT.
 






generic relay

If the original stock relay has been replaced with a generic single pole, double throw relay with pins numbered 30, 87, 87A, 86 and 85 then you should insert the jumper into the contacts for pin 30 to pin 87. The fuel pump should immediately run and several amps of current will flow thru the jumper.
 






If the original stock relay has been replaced with a generic single pole, double throw relay with pins numbered 30, 87, 87A, 86 and 85 then you should insert the jumper into the contacts for pin 30 to pin 87. The fuel pump should immediately run and several amps of current will flow thru the jumper.

You said something there that got me thinking, You say if I have a generic relay, BUT I don't?? It is a stock Ford Relay, when I checked it I had my brother look up the fuse panel in the manual, so I went back and checked the fuse box layout myself, turns out he had given me the WRONG relay!:mad:

He gave me number 4, which turns out is the PCM Power Relay, so i jumped 30 to 85 on the PCM Power Relay and burned my fingers, and not the Fuel Pump Relay at all. It was only jumped for a second, just long enough to burn me and me to pull it out, I never let go of it when I put it in.

Note to Self: Always double check torques, measurements and wiring diagrams yourself.

Any chance I could have caused any damage to the PCM circuit or parts and if so where would I start checking?
 






Fuse 10 blown?

You shorted the power to the PCM Power Relay to ground.
PCMPowerRelay.jpg

That should have blown Fuse 10 (30 amps) in the Battery Junction Box.
 






You said something there that got me thinking, You say if I have a generic relay, BUT I don't?? It is a stock Ford Relay, when I checked it I had my brother look up the fuse panel in the manual, so I went back and checked the fuse box layout myself, turns out he had given me the WRONG relay!:mad:

He gave me number 4, which turns out is the PCM Power Relay, so i jumped 30 to 85 on the PCM Power Relay and burned my fingers, and not the Fuel Pump Relay at all. It was only jumped for a second, just long enough to burn me and me to pull it out, I never let go of it when I put it in.

Note to Self: Always double check torques, measurements and wiring diagrams yourself.

Any chance I could have caused any damage to the PCM circuit or parts and if so where would I start checking?

I went through this almost exactly one year ago. I had no pump running on my 02 Explorer XLT . When I hit my tank with a rubber mallet , it would intermitted run. Then it stopped completely .
I cut an excess hole in the floorboard just behind the passenger seat and replaced the whole fuel pump and sending relay. With an after market one
The new pump would not run either ? It turned out that a fuse had blown when the old pump quit . There a couple of fuses that feed the fuel pump in the B/J/B . I was unsure of which one it was so I pulled them all and checked them. One was blown.
Once I replaced it the new pump ran fine and has been ever since . So my headaches started with a fuel pump that was faulty .
I have the stuff I did written somewhere . But I would have to dig it up. I even purchased the whole set of Ford shop manuals as the Chilton book is very vague .
It was a good thing I cut the access whole rather then dropping the whole tank so everything was much easer to trouble shoot.
 






I checked the "#10 30amp PCM Power Relay Maxi Fuse", the "#6 10amp Powertrain Control Module Mini Fuse" and the "#9 20amp Fuel Pump Relay and RAP Module Mini Fuse". They were all good. So that's good, thank you 2000StreetRod.

jessef113, can you post a few pics of where you cut out the floor board? or you could PM them to me if that would be better. I would really like to go that route too, I wish the engineers made an access hole there anyway to begin with.
 






I checked the "#10 30amp PCM Power Relay Maxi Fuse", the "#6 10amp Powertrain Control Module Mini Fuse" and the "#9 20amp Fuel Pump Relay and RAP Module Mini Fuse". They were all good. So that's good, thank you 2000StreetRod.

jessef113, can you post a few pics of where you cut out the floor board? or you could PM them to me if that would be better. I would really like to go that route too, I wish the engineers made an access hole there anyway to begin with.

I have several pictures of the whole but don't know how to get them on here?
If you want send me your your e-mail I can send them to you .
You have to take out the pass seat and the seat behind it . I bought the fuel pump new on E-Bay from trueblueautoparts , Good seller and the whole thing was only only $99.95 free shipping and have had no issues with it
 






This is excellent. Help me chase down my issue.
I found the PCM relay was not making good contact in the socket.
Problem solved, and 30psi fuel pressure when running, about 22psi when the key is turned on.
Is there something like this post to help trouble shoot why a blower motor has one speed. Off and High...I just changed the resistor unit and no difference...Off and High only. Relay's appear good, fuses ok too. 2000 XLS w/AC auto X series VIN 4.0 OHV
Thanks again for posting this item, save me a ton of work
T
 






wrote a reply. . didn't need to lol never mind
 






I have been having the same issue. Except nothing would work but to prove fuel I took off the air cleaner connection and sprayed starter fluid in the throat and tried it again and same thing crank but nothing else. Then I decide to spray one more time and button up the air filter and then tried it and it started and has run for the last 2 weeks. My question is, could the fuel pump cause this or is there a gremlin in the vehicle? I did check and tried each time, so I would know what cause it, relays, inherit switch, fuse all OK. I did have spark, checking it with a timing light.
 






measure the fuel pressure

Your vehicle is 14 years old. If you still have the original fuel pump it could easily be intermittently non-functional. The electrical brushes in the motor wear down and the brush springs become weak. Also, not replacing the fuel filter every 30K miles makes the pump work harder to push fuel thru the clogged filter. Your fuel pressure should be about 65 psi.
 






The vehicle only has 113,000 miles and I have seen a cut away view of the fuel pump and the brushes are coming down so gravity is in play also. The fuel filter was just replace a year ago and the filter was clean. I ask, because I was told that it is possible the air-mixture thing in the air throat my cause the same problem and with spraying the starter fluid in might of cleaned off some dirt that might of cause this. I haven't heard of this before. Any other thoughts? I do acknowledge that I am just trying to convince myself that it can't be the fuel pump.
 



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This is a update on the problem I had and still have on my 2001 Explorer. I still have to spray starter fluid once in a while to get it started when it only cranks over. I have clean the MAF sensor because a Ford tech told me that could cause the problem. To no ad vale this does not seem to be the problem. I have been able to start it once it gets started for months and then it just cranks and I spray it and everything works again. To me it axes like the problem would be a cold start problem. But once it starts I turn it off and disconnect the MAF sensor and still will start so that seems to eliminate the MAF sensor which has a temp sensor as part of it. Any ideas would be appreciated.
 






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