2004 Lincoln Navigator - Crank - No Start Possible non-serviceable fuel relay or fuel pump

[tedallen]

I had driven to a doctor appointment with no issues and when I attempted to start the Navigator to leave it cranked, but would not start. I think on the first few cranks it might have sputtered slightly, but that could have been residual fuel in the rails.

I checked to make sure the crash detection fuel cutoff switch had not been triggered and it had not. I tested fuse #34 (20A - PCM, IAC solenoid, MAF sensor, Fuel injectors, Fuel pump relay, Fuel pump shut-off switch, Fuel pump motor) and it was good. I disconnected the second connector from top left of the fuse panel in the passenger front kick panel (7 connectors on the top of the face above the fuse panel cover) and checked the bottom left output pin in the panel (where the green wire with yellow tracer from the connector would connect) for voltage when turning the key to the KOEO position and briefly saw close to 12v, but not for the 2-3 seconds I would expect for the fuel pump prime. I then dropped to around 6v and stayed there, even when cranking the engine. That led me to believe it is an issue with the integrated fuel pump relay.

I then ran 12v DC directly from the positive terminal of the battery to the green/yellow wire in the connector that leads to the fuel pump. I assumed I would hear the fuel pump constantly running and when the vehicle was cranked it would start if the fuel pump was working. However, I did not hear it run and the vehicle would not start.

Is there anything else in line to the fuel pump other than the fuel pump shut-off switch that could potentially prevent current from reaching the fuel pump other than a bad connection some where in that path?

I find it hard to believe that both the fuel pump relay and the fuel pump (or something in that path) happened to fail simultaneously. I replaced this fuse panel about 7 years ago for a failed fuel pump relay. I have never replaced the fuel pump in this vehicle, but I did have to drop the tank and replace one in a 1997 Ford Expedition probably 14 years ago.

I appreciate any and all input. We are expecting bad weather her in the Charlotte, NC area starting tomorrow, so I likely won't be able to work on it for the next couple of days. If I can get to Pull-A-Part before bad weather hits tomorrow morning, they have a 2003 and a 2005 Navigator there and maybe at least one of them has the fuse panel.

Thanks,

Ted

 

[Action]

You might want to confirm it is a fuel issue by spraying fuel into the throttle body to see if anything fires. If it does you have confirmed it is a fuel issue. Or lack of fuel pressure.

The in tank pump is powered up from relay in battery junction box to inertia switch. The wire from the inertia switch to the pump is pink and black.
The in tank pump is gets ground from the PCM. The wire from the pump to the PCM is black.

The fuel pump assembly has a module and a tank pressure sensor integrated into the assy with input by the PCM. The module will vary fuel pump pressure.

Action

 

[tedallen]

You might want to confirm it is a fuel issue by spraying fuel into the throttle body to see if anything fires. If it does you have confirmed it is a fuel issue. Or lack of fuel pressure.

The in tank pump is powered up from relay in battery junction box to inertia switch. The wire from the inertia switch to the pump is pink and black.
The in tank pump is gets ground from the PCM. The wire from the pump to the PCM is black.

The fuel pump assembly has a module and a tank pressure sensor integrated into the assy with input by the PCM. The module will vary fuel pump pressure.

Action

Thanks Action. I had looked for some starting fluid at the house and didn't have any to spray in the throttle body, but I will pick some up this morning. The there are a couple of other things that had happened over the past several months that I should mention. The first thing is that a message started coming up stating "check charging system", yet the battery was fully charged and the alternator was putting out the appropriate voltage. I have had no issues with the battery discharging and it is about 12 months old. I do have issues occasionally with the Positive battery cable not making solid contact on the terminal. It is the original style cable with that vertical screw clamping system that over time gets to the point where it doesn't want to adjust properly. About 3 weeks ago, my wife had to wiggle it to make contact and around that time the audio output from the factory stereo system stopped working (the stereo powers on, there is a CD load error, but no sound when tuned to radio stations, etc.).

I know there are issues with drain holes in the front of the moonroof getting clogged, resulting in water running down the front door frame body pillars along the windshield to where the fuse box is located in the passenger front kick panel and the driver front kick panel (apparently there is a large connector in that location that can get wet and cause many problems). I haven't noticed any moisture on the passenger side, but I have not removed the driver side kick panel yet, but the carpet feels dry.

You mentioned that the PCM completes a ground for the fuel pump in addition to the fuel pump relay completing the positive connection fro the green/yellow wire coming out of the fuse box. Do you happen to know if the PCM should be completing that ground as soon as the key is turned to the KOEO position and maintaining the ground until the key is switched to the off position? I assume it must be. Do you know what the PCM would be monitoring that would result in it removing the ground signal to the fuel pump? Do you know which connector and pin within said connector at the fuse box panel is the ground to the fuel pump being controlled by the PCM? If I can locate it I can jumper it to ground along with jumpering the green/yellow wire to 12v battery power to see if that will cause the fuel pump to run.

Does the connector to the inertia fuel shut-off switch have both the positive and the negative/ground wires for the fuel pump in it? If so, if I can access that connector I should be able to apply power and a solid ground to those wires to see if the fuel pump will run while eliminating a large portion of the wiring.

Thanks again for all your assistance!

Ted

 

[Action]

It is not as easy to copy pictures and diagrams from the internet as it once was. (There are blocks to prevent that from hapopening)
In addition this site disables features like attachment loading. So I can not attach a picture of the diagram

So the link I have to the diagram is here.

https://www.justanswer.com/ford/43gki-ford-expedition-4x4-ford-dealer-fuel-pump-assembly-fuel-tank.html

That site will want to engage you in your quest to make a repair.

You said, "Does the connector to the inertia fuel shut-off switch have both the positive and the negative/ground wires for the fuel pump in it?"
The short answer is no.
The long answer is there are 3 wires to the inertia switch in a connector (C204) at the inertia switch.
Power from the fuel pump relay - DG/YE
Power out to the instrument panel fuel reset switch indicator - GY/OG
Power to in tank fuel pump - PK/BK

The fuel pump assembly has 7 wires in what may be 2 connectors at the fuel pump assembly.
Power from the inertia switch to pump motor - PK/BK
Ground for the pump motor to the PCM - BK - note this is the fuel pump motor ground and it is done at the PCM
Power from instrument panel to fuel pump control module - YE/WH
Ground for fuel pump control moduel to PCM. - BK/OG - note, just like the ground for the motor, this ground is at the PCM as well. Likely this ground is interupted by the PCM to achieve diffeent fuel pump pressure.
Three other wires for the fuel tanl pressure sensor. One of the three go to the PCM. Wire colors for those 3 wires are as follwos: RD/PK, BN/WH, GY/RD

If you want to see if the fuel pump will run by by-passing all controls, thiis would have to be done at the tank.
Remove connector at the pump.
Ground the pin on the pump that goes to the BK wire.
Connect 12v+ to the pin on tyhe pump that goes to the PK/BK wire
DO NOT HOLD POWER TO THE PUMP for more than a few seconds. The pump is not designed to operate for long at full power. The power is modulated by the PCM based on demand. Damage will occur if the pump is run at full power continously.
The PCM controls the fuel pump operation (cycling on and off) and pressure by controlling the fuel pump module. The fuel pump module is part of the fuel pump assembly.

Hope this helps

Action

Other answers -
The PCM has multiple grounds. I do not know for sure and I woudl bet the ground from the pump to the PCM is connected always. Key on or key off.
Once the ignition switch is move to on (KOEO) the pump will be powered up by the power from relay in the battery junction box, to the inertia switch to the pump. This is instantaneous.

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[tedallen]

Thanks Action. I greatly appreciate all your time. Unfortunately, I was unable to access the diagram(s) you linked to (they showed as "Confidential" on the image icons on that page and were not clickable).

I had ordered a digital repair manual for a 2004 Lincoln Navigator a couple of years ago (it was supposed to be constructed based on the VIN of my vehicle). However, I don't think the electrical diagrams in it match with my vehicle. For example, it shows F1.9 (the 9th horizontally oriented fuse from the top left down the side) as being the fuel pump fuse. However, my physical owner's manual shows F1.34 (the 4th vertically oriented fuse from the top left, just to the left of the second relay from the top left) as the fuel pump relay. I saw a video where it appears that maybe F1.9 was the fuel pump driver module/fuel pump/inertia switch fuse location on 2005-2006 Navigators. So, I may only be able to use replacement junction boxes for 2003-2004 year vehicles. I don't believe the 2003-2004 Navigators have the fuel pump driver module mounted on the driver's side rear frame rail (mounting bracket for it visible through the left rear wheel well), but I am going to look to verify.

I should have also mentioned that the rear liftgate stopped automatically opening/closing when you push down on it (to close) or open it manually. I think this happened around the same time my wife last had to wiggle the positive battery cable to get the vehicle to start which we believe to be the time when the stereo audio output quit working.

The local Pull-A-Part shows a 2003 and a 2005 Navigator in the yard. The bad weather here ended this morning, so hopefully I can go check them out to see if they have the junction boxes in them and compare the part number on them to the one I had previously removed from my 2004 in February 2018.

In the meantime, I am going to try spraying starter fluid into the throttle body and checking to see if I can tell if there is a fuel pump driver module mounted on the frame rail.

 

[Action]

My 06 has that driver mounted to the fuel rail on the left rear side. About 8 years ago or so when that issue came to my awareness I found it, removed it, and cleaned it. Then I treated all of the plastic pieces and waxed the metal pieces Since I rarely get into dirt I foigued I was good to go.

YOur ride may be too old for taht fuel control.
And you have multiple issues. Rememer clean and tight or securely fstened should rule the electrical world.

I always get factory paper shop manuals, wiring diesgrams and any other publication that is available. (NOt just vehicles, any machine that has publications)
I have had bad luck with electronic versions in the past.
Ebay is a good source for many automotive things

Action

 

[tedallen]

Thanks Action. I confirmed that the vehicle will start when starting fluid is sprayed into the throttle body, so it is definitely a fuel delivery issue. I also confirmed that there is no fuel pump driver mounted on the driver's rear frame rail visible via the wheel well. I think I did find the "mostly" correct wiring schematic, at least for the 5.4L in the manual. However, it still references the fuel pump relay being independently fused on F1.9 (15 amp), with F1.34 (15 amp) fusing the MAF, PCM, fuel injectors and IAC valve. My factory owner's manual shows F1.9 being unused and F1.34 (20 amp) being used to protect the PCM, IAC solenoid, MAF sensor, fuel injectors, fuel pump relay, fuel pump shut-off switch and fuel pump motor.

I am going to attempt to remove the left-hand rear interior trim panel to gain access to the inertia full-shutoff switch tomorrow and see if it is receiving 12v on the DG/YE wire, and also see if the pump runs when I apply 12v to the PK/BK wire in the connector, which should be going directly to the fuel pump.

I know you mentioned that the fuel pump ground is controlled by the PCM, but unless I'm missing it, in the diagrams I am looking at I don't see that the PCM enables/disables the ground to the pump.

 

[tedallen]

I got the right-rear trim panel removed (enough to get to the inertia switch and unplug it, dropping a 7/32" socket somewhere in the process). What a pain that was. I tried jumping 12v from the battery directly to the PK/BK wire in the plug, which as I understand should go directly to the fuel pump. I didn't hear any signs of it running and an attempt to start the vehicle failed. Unfortunately, the battery was getting low at that point. I also tried checking the voltage coming into that connector on the DG/YW wire. I was expecting to see 12v, at least for a couple of seconds to prime the pump when the key was switched to the KOEO position, however, I only saw a little over 6 volts that persisted. I'm going to reinstall the battery tomorrow morning and try to check again. I did order a couple of replacement relays to solder into the CJB if I need to go that route, but it is looking like I may have to drop the fuel tank, even if the relay is also bad.

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[tedallen]

So, with the charged battery installed, I was still only seeing around 6v on the DG/YW input into the inertia fuel-shutoff switch. I then tried jumping 12v directly from the battery positive terminal to the PK/BK output wire terminal in the inertia fuel-shutoff switch connector to see if the pump would run. I heard nothing and the vehicle would not start. I know it sounds crazy, but it almost seems like there is a problem with the fuel pump and the fuel pump relay. Maybe the fuel pump failed when trying to start the vehicle and overheated the relay. I did order 2 replacement relays that are supposed to work on the PCB in the CJB. If I can't find one at Pull-A-Part that matches the part number of mine I may just try pulling mine, taking it a part and trying to replace the relay. Either way I have a feeling I will have to drop the fuel tank and replace the fuel pump as well.

 

[Action]

less than 12 volts at the inertia switch is a problem too.

Action

 

[driller]

While not intimately familiar with the 2004 Navigator fuel pump circuitry, two questions come to mind reading through this thread.

Does the vehicle actually have a FPDM(Fuel Pump Driver Module)? I know past Lincolns of that era employed such and they can be problematic. It is basically a solid state variable voltage device supplying power to the fuel pump as commanded by the PCM. I've seen several instances where the FPDM fails and the fuel pump is fine. I'm not sure if this is applicable or not. If the FPDM is integral to the fuel pump assembly, applying 12V at the inertia switch would do nothing for the problem.

Is the fuel pump relay mechanical or solid state? There even could be both. Again, past Lincolns of that era employed a solid state relay integral to a Variable Control Relay Module for normal "low speed" fuel pump operation and a mechanical relay as a bypass for "high speed" fuel pump operation. Just another thought.

Proper diagnostics would require a wiring diagram at a minimum and likely a PowerTrain Control and Emissions Diagnosis Manual for the vehicle.

Long gone are the days of a simple relay and simple fuel pump. Good luck and keep us posted.

 

[tedallen]

Thanks @Action and @driller . The 2004 Navigator does not have a fuel pump driver module, or if it does it isn't mounted on the driver side rear frame rail and visible through the fender well. I don't see any mention of it in the owner's manual fuse/relay section and the digital service manual I purchased doesn't show it either, however, the electrical schematics in it aren't matching with my owner's manual completely (e.g. service manual shows the fuel pump on dedicated fuse F1.9 and I'm quite certain my fuel pump is on F1.34 along with fuel injectors, MAF, etc.

As for the voltage at the inertia switch, when I had originally checked the voltage by back-probing the DG/YW wire in the connector at the central junction box I was seeing around 13v, but very briefly when the key was turned to the KOEO position. Definitely less than the 2-3 seconds to prime the pump. However, after charging the battery and having it tested to confirm it is good, when I check voltage of the DG/YW wire in the connector at the inertia fuel shut-off switch I couldn't ever see it showing above 6-7 volts. Maybe the issue has gotten worse during testing. However, I did run 12v directly to the PK/BK wire in the inertia switch connector and the vehicle still would not start and I never did hear any indication the pump was running with the key off and all quiet.

The CJB did have an unblown 20 amp fuse in F1.34, whereas the owner's manual showed it as a 15 amp and the service manual showed 15 amp fuses in both F1.9 and F1.34. I wonder if the fuel pump could have overheated and failed and in the process drawn enough voltage to damage the soldered in fuel pump relay on the PCB of the central junction box, but not enough to blow the 20 amp fuse?

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[Action]

Based on the wiring diagram I saw there was no fuel pump driver module. for the 2004 model year.

I am thinking your digital service manual is not factory. May be more generic

I have no clue about fues location and/ir function.
However the fuel pump will not over heat based on a fuse. It over heats because of some other factor.
A fuse is an electrical protection device. It allows current to pass through it with a limit. Once the limit is reached the fuse stops current flow.
And a fuse is a current limiting devise not a voltage limiting devise.

With the exception of the power generator (alternator) there can be no voltage greater than battery voltage. Battery voltage is limited to 12.6 volts.

Action

 

[tedallen]

Thanks @Action. You are correct. I was seeing around 12.5v very briefly in the KOEO position on the DG/YW wire at the CJB. However, if it is happening now it is so brief that I can't detect it with my meter and naked eye. When checking now it is in the 6-7 range at most, even when cranking the engine (when measured at the inertia switch connector.

But even with battery voltage applied directly to the PK/BK wire in the connector at the inertia switch, which should send power directly to the fuel pump, it does not run.

I contacted the company that I got the digital service manual from and they claim the wiring diagrams are correct for my VIN, but I know they can't be since my original CJB didn't even have a fuse in the F1.9 location and it ran until the soldered in fuel pump relay failed in it.

 

[Action]

Shop manuals
This one is generic. The data information may work for most years just not all years. Any time multiple years are listed, THAT IS A PROBLEM. The DVD/CD is good for a coaster for your favorite cold beverage. IMO

Ford / Lincoln / Mercury - Service Repair Workshop Manual 1996-2008 on USB | eBay

Contains step-by-step procedures, detailed illustration, diagrams, and explanations that will guide you through your servicing and repairing of your vehicle. This is high quality Software and fully indexed!

www.ebay.com

The shop manual is a 2 volume set. Like this listing

2 PCS 2004 Ford Expedition Navigator Workshop 1&2 Factory Repair Manuals OEM | eBay

Find many great new & used options and get the best deals for 2 PCS 2004 Ford Expedition Navigator Workshop 1&2 Factory Repair Manuals OEM at the best online prices at eBay! Free shipping for many products!

www.ebay.com

If you gt this on a DVD/CD it would be OK. BISKO sells these. And for me it is hard copy only.

In addition there is a wiring diagram. Like this

2004 FORD EXPEDITION LINCOLN NAVIGATOR WIRING DIAGRAMS SHOP MANUAL | eBay

NICE ORIGINAL FORD WIRING DIAGRAMS SHOP MANUAL AS USED WITHIN THE DEALERSHIP FOR REFERENCE AND FOR THE SERVICE DEPARTMENT. THIS IS AN ORIGINAL FORD PRINT IN GREAT SHAPE, NOTHING BEATS THE ACCURACY AND DETAIL OF AN ORIGINAL FORD PRINT. FEEL FREE TO ASK ANY QUESTIONS. MISM15.

www.ebay.com

Action

 

[Action]

12 volts applied to the fuel pump (or the PK/BK wire from inertia to pump) should cause the pump to turn on. There may be several reasons the pump does not turn on.

Pressure has reached maximum designed pressure. No more pressure needed.
The ground side of the pump is not completely connected.
There is a wiring harness issue from the inertia switch to the pump. There is a splice and a connector between the inertia connector and the fule pump connector.
Or the fuel pump is not operating.

I may be in error as to the ground side of the pump at the PCM. (There are applications like this)
I am looking at a very small diagram.
This site no longer allows attachments because I have blockers turned on. (Other forums I visit do not have that limited feature. And that is a discussion for a different thread)
And the website is protected to not allow saving of pictures.

But a factory wiring diagram would have that detail.

Action

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[driller]

As much as I hate to say it, oftentimes there is a condition referred to as "death by diagnosis". In layman's terms, all the tests and diagnostics lead nowhere.

Whenever I have encountered similar situations, I tend to step away from all the tests and diagnostic routines and for lack of a better term, go with my gut instinct.

Story of case in point... our '06 Town Car once started exhibiting problems with the wipers. Simple problem? Not wanting an expense of a trip to the dealer, I decided to fix it myself. I don't recall all the details but there were literally days of testing this and that and following the OEM shop manual diagnostic routines. There were over 100 pages in the manual for troubleshooting the wiper system. After finding no obvious fix, I surrendered and made an appointment with the service department of the local dealer. A couple days and a diagnostic fee later, I received a quote for several hundred dollars to R&R the wiper motor, the wiper switch, the wiper module amongst a few other items. Pretty sure they were as stymied as I was. I politely declined the repairs and returned home. The next day I went with my gut and picked up a wiper motor assembly from the local NAPA store. No more than four hours later, the wiper motor had been replaced and the problems were resolved.

I think you see where this is going.

 

[tedallen]

Thanks @Action and @driller . I went to my local Pull-a-part yesterday to see if the either of the 2 Navigators there still had the central junction box in them. They did not, however, I did find a 2004 Exception that did. I am going back later this afternoon (hoping it is still there) to remove it. If the part number of it matches either of the ones I know I have had in my vehicle match, I will buy it and stick it in to see how it behaves. The PBC-mounted relays that I ordered came in as well and even if the one from the salvage yard works, I am going to try disassembling the junction box I removed, try unsoldering the fuel pump relay from the PCB and testing it. If it doesn't meet specs, I'll try soldering in one of the replacements.

If things still aren't working, I'll be dropping the tank tomorrow (I'll try to look for the splice connector between the inertia switch and fuel pump connectors that @Action mentioned above.

One thing I don't think I mentioned previously is that the day I had driven it to an appointment t and it failed to start when I was leaving it had been raining. I know of the issues with the drain holes from the moonroof getting clogged and water going down into the pillars by the windshield and potentially causing issues, but I didn't see any signs of that. Maybe that inline connector between the inertia switch and fuel pump is an issue.

I got a new fuel filter as well, so I'll be replacing it even if the pump starts working.

Ted

 

[tedallen]

@Action and @driller since I already had the relays, I decided to try taking apart my central junction box to look at the fuel pump relay soldered to the circuit board. Sure enough it had a bulge on the side toward one corner and the solder joint and portion of the pin coming through the circuit board in the corner is burnt. The circuit board looks ok so I'm going to try unsoldering the relay and soldering a new one in. Wish me luck. If I can post a picture later I will. Fingers crossed this solves all of the issues with fuel delivery, but I'm worried it won't. It definitely needed fixed though.

Ted

 

[tedallen]

@Action and @driller I soldered a new relay on the CJB PCB and the results are the same. I am atill only seeing 6v on the DG/ YW wire both at the CJB connector and the inertia switch connector. I’m headed to Pull-a-Part to see if I can get one that matches the part number before they close.