2003 5.4 EB Fuel Pump Relay

[Bedrck47]

For one expy girl tried to repair the fuse box and failed Can't say why as I have no idea how it was done or if she used an old relay. Then she listened to someone that told her a fuse box for an 04 nav would work and it did to some degree. After having been thru this problem many times with other members I sent her some information and even a comment from a truthful seller on e-bay that knows the part numbers have to be the same and Also from my experience that the 03 uses two different fuse boxes I have not heard back from her since Typical of many new members.

Now you need to decide if you want to take my advice or continue to search the forum or google for someone else's advice. The PCM doesn't not vary the voltage to the fuel pump.

Get yourself a new fuse box or one from a salvage yard and hope its in working condition or replace the relay on the board

If you have tried the jumper and the expy is running you now know the relay is faulty.

Sorry for being blunt

 

[CertusExpo]

I'm not ignoring your advice. It's spot on.
I definitely will ensure that the replacement fuse box part number matches.

The ideas I have with a standard but heavy duty relay is a long-term improvement over OEM if I can figure it out. Especially the ability to adjust the voltage (flow) real-time using the digital readout on the potentiometer.

 

[Bedrck47]

In the post that you referred to me the OP has an 05 expy The 2nd gens have a fuel pump relay that is soldered to the circuit HOWEVER the 03 and 04 years use the same fuel pump motor circuit THE 05 and 06 have the addition of a fuel pump drivers module that controls the fuel pump motor The 03 and 04 is controlled just by the relay.

The operation of the relay and the fuel pump drivers module are not the same

But both systems had their own problems the FPDM was subject to failure due to corrosion and would leave you high and dry at least with the relay a jumper would get you running but if the pump was the problem better put on your walking shoes

 

[CertusExpo]

In the post that you referred to me the OP has an 05 expy The 2nd gens have a fuel pump relay that is soldered to the circuit HOWEVER the 03 and 04 years use the same fuel pump motor circuit THE 05 and 06 have the addition of a fuel pump drivers module that controls the fuel pump motor The 03 and 04 is controlled just by the relay.

The operation of the relay and the fuel pump drivers module are not the same

I missed this detail. Which is a very important one. Thanks for the catch Bedrck.

 

[CertusExpo]

Bedrck,

Quick question. Would you happen to know what size sockets and/or tools will be needed for the uninstall/install?

 

[CertusExpo]

Got the info off mine.

View attachment 20170923_123203.jpg

 

[CertusExpo]

Found one

View attachment 20170923_140008.jpg

And it came out of an Expy that had all the windows intact and the doors were all closed tight.

 

[Bedrck47]

Did you get it installed yet

 

[stamp11127]

I just love it when people take the extra second to unplug the connectors instead of cutting wires...

 

[CertusExpo]

Did you get it installed yet

Not yet, frigging hot. Gonna wait until the sun goes down.

 

[CertusExpo]

Bedrck, how does this one un-clip and come out? I don't want to damage it by doing it incorrectly.

 

[Bedrck47]

Should be a tab to press or maybe the two red buttons

 

[CertusExpo]

Well.... Same result with the replacement fuse box.
She just cranks and cranks.

Connecting the jumper again results in start-up.


Ugh. Now what.

 

[Bedrck47]

First remove the jumper
Then put the key in the run position
Then read the voltage into and out of Fuse #34
Post the results

 

[CertusExpo]

I had to do rear brakes and found my multimeter junked so I'm making a run to my local Fry's a little later.

 

[ogre20012001]

Ok so can anyone say what is the difference in the fuse boxes???
I have an 03 eb. In June I was on vacation when r303 burned up on my expedition.
I went to a pick and pull yard and after searching many expeditions I found an 05 with a fuse box.
I opened them up and noticed the circuit board was different with different part numbers. However the plugs were the same and all fuse locations were the same.

I didn't know their were two different fuse panels in 03 or that they were different from other years.
I simply plugged the new one in and my expedition ran just fine and all things worked. Still have not had a problem with the new fuse box.

So I'm just wondering what the difference is in fuse boxes.
Thanks for the help this site has given me and for the knowledge that is found on this site.


Sent from my iPhone using Tapatalk

 

[CertusExpo]

Okay Bedrck,

13.51v on top
12.50v on bottom

Both with fluctuations of +/- .5

 

[Bedrck47]

Ok so can anyone say what is the difference in the fuse boxes???
I have an 03 eb. In June I was on vacation when r303 burned up on my expedition.
I went to a pick and pull yard and after searching many expeditions I found an 05 with a fuse box.
I opened them up and noticed the circuit board was different with different part numbers. However the plugs were the same and all fuse locations were the same.

I didn't know their were two different fuse panels in 03 or that they were different from other years.
I simply plugged the new one in and my expedition ran just fine and all things worked. Still have not had a problem with the new fuse box.

So I'm just wondering what the difference is in fuse boxes.
Thanks for the help this site has given me and for the knowledge that is found on this site.


Sent from my iPhone using Tapatalk

You got lucky The 05 has circuits that the 03 doesn't for example the fuel pump circuit is different

In the 03 the charging circuit is different one box has fuse #9 the other box doesn't
the 03 had early and late production models

 

[ogre20012001]

This is my junk yard find




This is my original...


Melted relay.

I didn't think to take pictures of the circuit boards but like I said all looked identical except boards and so I tried it.
Haven't had a problem with it and every thing works.
So I was just wondering if anyone knew the minor details on the difference.

My junk yard box came loaded with all the fuses so when I compared fuses they were all the same so I gave it a shot...

I didn't learn about the 03 having different boxes than any other expedition till just the last couple of days when I was trolling though different threads just for the fun of something to do...


Sent from my iPhone using Tapatalk

 

[CertusExpo]

In case it was lost in the mix....

13.51v on top
12.50v on bottom

Both with fluctuations of +/- .5