04 dies, batt light comes on. Alt/batt both good

[Jacob13254]

Hi, new to the forum. My 2004 5.4 expy,135k has recently been dying at idle are during driving. Randomly. Batt and check gage light comes on. It always fires right back up. At first suspected charging system but alt/batt test good. terminals and wires good. battery isn't drained after it dies. Now I'm suspecting dying fuel pump. Not throwing any codes and well maintained vehicle here. I'm stumped any help appreciated, Jacob.

 

[stamp11127]

Welcome to the site.

The 2003 and 2004 have had issues with the fuel pump circuit. You would need to see what the fuel pressure is on the fuel rail the next time it dies to determine if the problem lies in that area.

 

[Jacob13254]

Circuit

Thanks for reply. Would that mean the relay, wiring going to it are?

 

[Bedrck47]

How long have you owned the Expy?
Has the fuel pump ever been changed?
Fuel Filter changed?
As Stamp suggest get the fuel pressure reading at the rail.

The problem with the fuel pump circuit is that the relay is soldered to the circuit board inside of the fuse box. The relay starts to burn and causes a lose of fuel pressure. It normally starts with the symptoms you are describing. You can pull the cover off the fuse box and using a bright light and maybe a magnifying glass look at the area around the 5 relays in the middle of the fuse box to see if you can see any signs of over-heating or burn marks. Post your findings

 

[Jacob13254]

Had it 2 yrs as far as I know its original pump/filter. Soldered in? Damn sounds like a unnecessary pita. I'll check it out. That doesn't sound cheap. If that's my problem I may have to go against my better judgement and get box on salvage yard atleast til I got more cash

 

[stamp11127]

Trouble with the salvage yard boxes is that they may be in the same or worse shape than the one you have. These are repairable if you have the soldering skills and tools.

 

[Bedrck47]

Search on youtube and look at the following videos.

2003 Ford Expedition Fuse Box Problem & Replacement

Ford Expedition P0231 and Stalling Diagnosis

These will give you some information as to what you may be experiencing.

If you decide to pull the fuse box look at the sticker on the side and you will see the date of Mfg. That will show you if the fuse box is the original or if the date is newer than 2003 then you will know that the fuse box has been replaced.

Again post your findings on the forum

 

[Jacob13254]

Box is original. Having a hell of a time getting it out. Some of the wire connections are roadblocking me. A couple I don't even see are feel a clip are anything. Black thick wire loom connection closest to firewall and wide connection on top. I'm tempted to just wire on a new relay for pump triggered by ignition 12v. But hesitant since may be no point.

 

[stamp11127]

Have patience, cuss at the designers a little and it will come out. And remember, if you jerk it out you are not getting it back in easily.
Prove the failure before "fixing" it.

 

[Bedrck47]

You need to disconnect the battery under the hood first then disconnect the cable at the fuse box Then there is another bolt that holds the box to the body Once all of that is done the cables should be easy Try using a good flashlight and an inspection mirror to help you see what you are doing. Take your time and don't force anything. It will make it easier for you. If you get frustrated then walk away for a few minutes and regroup

 

[Skauber]

Once you get it out, inspect the relay, if it's burnt you have three options:

1. (Cheapest) Buy a new relay, Omron has some that fits for a few bucks. Solder it in yourself and reassemble.

2. Send the fuse box to a reputable repair service to have it repaired.

3. Buy a new fuse box from the dealer or elsewhere.

 

[Jacob13254]

Got a box outta the junkyard for $10 due to money issues at the moment. Been 400 miles so far with no issues. Hope it holds up. Thanks for the help everyone

 

[Jacob13254]

Put a used box in. 400 miles, so far so good

 

[Bedrck47]

Take the old one and have it rebuilt keep it as a spare. Also check the date of Mfg. on the one you got from the junk yard If it is from the same year you may end up having the same problem again

Thanks for the update

 

[Jacob13254]

Kept the old one. Expy I got it out of got rear ended and only had 70k on it.