Another fuse box replacement ....

[Don Hall]

Had the same problem with the same solution.

Glad it all worked out for you.

 

[slowkid]

Is there another company BESIDES Fordfusebox.com that refurbs these and upgrades to the 20-amp relay for the fuel pump? The guy at Fordfusebox is kind of an @$$.

Here's the backstory: I'm looking for an 03-04 Expy because, while my 18 Expy Limited is a wonderful vehicle, it sits in the driveway 5 days a week since I have a company car and I just can't justify the payment. I've lurked on this forum for years as I've now owned each generation of Expedition. I read this thread before buying the truck and I saw no signs of heat on the adjacent relays. Yesterday, on my third day of ownership, I'm out inside of it with the heater on "high" after shampooing the carpet while cleaning the years of filth off of every surface. Sure enough, the engine sputters and dies. I have a crank/no start with it and let it sit for about 3 minutes and it will start back up.

I checked the fuse box and it was physically very warm. I realize I had been running the heater on the floor setting for quite a while and it probably contributed to the relay overheating. I subscribe to the "an ounce of prevention is better than a pound of cure" notion, so I'm going to go ahead and replace it. So, I contact Fordfusebox.com to see if they upgrade the F8VF-BA 15-amp relay to the 20-amp G8QN relay. The reply comes back that they use original OMRON relays. I ask again for which part number they use and I tell him why I'm asking, and I get this reply:

"we install ORIGINAL omron relays. they will work in the next 20 years.

the only problem is to find ORIGINAL OMRON relays in the sea of counterfeighted [sic] OMRON relays on the market

DO NOT READ INTERNET"

From a common sense standpoint, I don't think Ford used counterfeit relays from the factory. Those 15-relays overheat and fail. Ford later changed to a 20-amp relay. So, I don't think "the internet" is the problem and that guy is an @$$ who won't get a dime from me.

I've never been good at soldering and I like the idea of having the whole fuse box gone through by someone who knows what they are doing, what are my other options because Google hasn't been any help?

 

[slowkid]

As a quick update to Mr. Fordfusebox.com, when I told him I would find another company, he resorted to calling me names. Seems professional. Just for anyone reading this thread and considering that website, I'd recommend going elsewhere.

 

[CertusExpo]

I don't have the info or pictures right now but I had my fuel pump relay fail AFTER I got off work in downtown Dallas a while back where I didn't want to be after dark and there was no way in hell I was paying for a tow 42 miles away out of pocket.
I do InfoTech for a living so I decided to troubleshoot it like any piece of hardware.

My point is this. I found a way to jumper the fuel pump itself with a paperclip and drive my butt home so I could repair it in my own driveway with access to all my tools.

I'll update this post tomorrow with the info and photos so my fellow Expy drivers won't be stuck on the side of the road anywhere.

 

[bret191]

I just rebuilt mine with higher amp relays and now I can replace the relay with out taking everything apart. I mad two pig tails and aftermarket relay holders, Digi has any parts you'll need.

 

[zanwahwarden]

So I know there is a bunch of people that like to replace the CJB (Fuse Panel). But remember that all you are doing is resetting back to the same potential problem being able to happen again. The circuit board was not designed properly to take the heat from those undersized relays. If the PCM relay is good, and you only fried the fuel pump relay, I recommend just putting an external relay on and wiring it in. There are videos to do this, but a lot of them suggest wiring it in improperly so that the fuel pump runs whenever the ignition switch is on. I have an 05 Expy and this is the proper way to wire in an external relay....

First... buy one of these external relay kits... its rated for 30 amps.
https://www.amazon.com/gp/product/B074QV54V1/

And one of these (mini fuse tap) ...
https://www.amazon.com/dp/B01LFXA5UA/

And you will need some inline power taps...
https://www.amazon.com/dp/B07WFPFY1C/



Then wire it in as follows...

Your relay has 5 wires. You don't need the center one. So all you need are the 30, 85, 86, and 87 terminals that correspond to the relay harness. 30 is power always on, 85 is a ground that activates the relay (it completes the pin 86 circuit), 86 is powered when ignition is on (engine running or not), 87 is power out only when the relay is engaged (this will go to the fuel pump)

The reason most videos are wrong is that they wire the ground to a normal ground. This means that the minute you turn on the car the fuel pump runs constantly. How its supposed to work is that the PCM has a ground going to the fuel pump relay that is only on 1.) when you first turn the ignition to the on position and its only grounded for the 2 seconds of priming then disconnects and 2.) When your car starts and it then needs constant power to the FPDM (Fuel pump driver module)

So what you want to do is to replicate that circuit that includes the ground from the PCM. Here is a way to do it that works the way it should...

First you need power to the new relay... fuse 9 (15) amps will work because its KOEO (Key on Engine Off).
Wire that Using a fuse tap to get power for the pump, fuse 9 (15A), wire that to 30 on your relay. Use a 20 amp fuse for the second fuse (put the 15 amp fuse on the lower socket the 20 amp on the upper socket. Basically you just made a new circuit.

On the C270A plug there is a red/yellow wire... that is Key on Engine off or on power. Basically power that only goes on when the ignition circuit is active. Use an inline tap to wire that to the wire that corresponds to 86 on your relay.

On C270B, there is a thinner guage black wire in the corner of the plug. This is ground from the PCM. On some years I believe its LT BLUE/Orange, but for 2005 its black. You can cut it or do an inline splice... I always opt for the inline splice for grounds. It is pin 12 of c270B and wire the harness side of it to 85 of your relay using an inline splice.

Now the relay should work, and you can test it before doing the final connection by turning the ignition on and you should hear a click from the relay. If this woks, you now just need to feed power to the FPDM.

The dark green/yellow wire of C270B feeds power to the FPDM... cut that and wire it to terminal 87 of your new relay.

Your car now has a better, and replaceable external fuel pump relay. Doing it this way will not fry your CJB and is easily replaceable if it were ever to fail again.

Thankyou David for the info saved me a hassle and a bit of money. Expedition left me stranded from bad fuel pump relay, luckily I was able to jumper a 12v+ wire to the pump via the dark green/yellow wire on plug c270k from fuse 9 auxillary power a few minutes before tow truck that I had called arrived. (Unplugged wire as soon as I parked at the house).

I started out at home by removing the fuse board and disassembling everything to get to the circuit board with 5 attached relays exposed. My integral fuel pump relay (middle one) was definitely burnt up and bubbled looking and the one node on the back was burnt up. I bought and soldered a new fuel pump relay onto the board but due to my soldering inexperience and the fact I tried to drill out the bad node that I couldn't melt with soldering iron to release old relay , I might have ruined that portion of the board where that fuel pump relay goes. I put it all together with the newly soldered relay, My expy started and ran for 5 minutes after starting and then failed or lost connection and back to square one which is where your fix came in handy and avoided me having to buy a new board or use an eBay repair service.

The reason I made an account and am posting here is because I think you had one error in your advice that might throw people astray, and that is the dark green/yellow wire on wire connector C270B to fuel pump driver module you had listed should actually be connector C270K dark green /yellow wire(assuming you had a typo unless there's multiple paths there). I tested amps after hookup and it runs for a second in key on to prime before going off and then starts up again after startup like it should. I found some drawings of connector locations to help locate connectors. I still gotta clean up the wiring but thank you for getting me going.

 

[robperry70]

Can someone please post a picture and point out which connectors are c270a, c270b etc. I am not good at reading wiring diagrams. Thank you

 

[robperry70]

So I know there is a bunch of people that like to replace the CJB (Fuse Panel). But remember that all you are doing is resetting back to the same potential problem being able to happen again. The circuit board was not designed properly to take the heat from those undersized relays. If the PCM relay is good, and you only fried the fuel pump relay, I recommend just putting an external relay on and wiring it in. There are videos to do this, but a lot of them suggest wiring it in improperly so that the fuel pump runs whenever the ignition switch is on. I have an 05 Expy and this is the proper way to wire in an external relay....

First... buy one of these external relay kits... its rated for 30 amps.
https://www.amazon.com/gp/product/B074QV54V1/

And one of these (mini fuse tap) ...
https://www.amazon.com/dp/B01LFXA5UA/

And you will need some inline power taps...
https://www.amazon.com/dp/B07WFPFY1C/



Then wire it in as follows...

Your relay has 5 wires. You don't need the center one. So all you need are the 30, 85, 86, and 87 terminals that correspond to the relay harness. 30 is power always on, 85 is a ground that activates the relay (it completes the pin 86 circuit), 86 is powered when ignition is on (engine running or not), 87 is power out only when the relay is engaged (this will go to the fuel pump)

The reason most videos are wrong is that they wire the ground to a normal ground. This means that the minute you turn on the car the fuel pump runs constantly. How its supposed to work is that the PCM has a ground going to the fuel pump relay that is only on 1.) when you first turn the ignition to the on position and its only grounded for the 2 seconds of priming then disconnects and 2.) When your car starts and it then needs constant power to the FPDM (Fuel pump driver module)

So what you want to do is to replicate that circuit that includes the ground from the PCM. Here is a way to do it that works the way it should...

First you need power to the new relay... fuse 9 (15) amps will work because its KOEO (Key on Engine Off).
Wire that Using a fuse tap to get power for the pump, fuse 9 (15A), wire that to 30 on your relay. Use a 20 amp fuse for the second fuse (put the 15 amp fuse on the lower socket the 20 amp on the upper socket. Basically you just made a new circuit.

On the C270A plug there is a red/yellow wire... that is Key on Engine off or on power. Basically power that only goes on when the ignition circuit is active. Use an inline tap to wire that to the wire that corresponds to 86 on your relay.

On C270B, there is a thinner guage black wire in the corner of the plug. This is ground from the PCM. On some years I believe its LT BLUE/Orange, but for 2005 its black. You can cut it or do an inline splice... I always opt for the inline splice for grounds. It is pin 12 of c270B and wire the harness side of it to 85 of your relay using an inline splice.

Now the relay should work, and you can test it before doing the final connection by turning the ignition on and you should hear a click from the relay. If this woks, you now just need to feed power to the FPDM.

The dark green/yellow wire of C270B feeds power to the FPDM... cut that and wire it to terminal 87 of your new relay.

Your car now has a better, and replaceable external fuel pump relay. Doing it this way will not fry your CJB and is easily replaceable if it were ever to fail again.

Ok followed instructions and it now starts but cuts off immediately. New fuel pump, new filter, and the relay.

 

[zanwahwarden]

Ok followed instructions and it now starts but cuts off immediately. New fuel pump, new filter, and the relay.

Did you wire it to the dark green /yellow wire from c270k because I believe David's post had a typo. I posted it right before your post along with the picture you are talking about

 

[robperry70]

Did you wire it to the dark green /yellow wire from c270k because I believe David's post had a typo. I posted it right before your post along with the picture you are talking about

I must have been typing as you were posting the pictures. lol. But yes I did do it to c270k. I had to arched some videos and did do that. My thing is that now it actually cranks but then shuts off as soon as I let off the key from start mode to run mode. I have tried the fuse in 9 and a couple others. I even switched the two relay wires (30 & 87) no change. I tried different grounds, no change. I know the original relay was part of my problem because it was crank no start and now it is crank with start. Just not continuous run.

I may have found the problem. I will let you know. Thank you in advance. The pictures are a great help