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Ron
Ron, ASE Certified Technician
Category: Ford
Satisfied Customers: 34179
Experience:  23 years with Ford specializing in drivability and electrical and AC. Ford certs and ASE Certs
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I have 2004 ford expedition that will not start. First the

Customer Question

I have 2004 ford expedition that will not start. First the starter would not shut off. Had to remove battery cable. I replaced the start relay & starter. Worked fine 5 or six times, then starter would not shut off again. Replaced ignition switch, but now I have no power to coil on PCM relay. Where could I be losing this?
JA: Is the power loss consistent, or does it fluctuate?
Customer: consistent
JA: Are you hoping to fix this yourself? What have you tried so far?
Customer: yes, I have checked fuses for PCM & they are good
JA: Anything else you think the mechanic should know?
Customer: The digital display on the dash does not come on with key on now
Submitted: 6 months ago.
Category: Ford
Expert:  Ron replied 6 months ago.

Hello and thank you for your question.

What size engine due you have in your Expedition?

Customer: replied 6 months ago.
5.4
Expert:  Ron replied 6 months ago.

Okay thank you for that, the PCM relay and coils get there power from two fuses both located in the interior fuse panel. These fuse are the F1-28 fuse and the F1-34 fuse. Start first with checking these to make sure both have power in and out of them. See the wiring diagram in the link below for reference. Check these and post back with your results and we can work from there.

https://dl.dropboxusercontent.com/u/104923897/Fude%20PCM%20Aug%204.pdf

Customer: replied 6 months ago.
both fuses are good
Expert:  Ron replied 6 months ago.

Okay then now you need to check and see if you have key on power in and out of the EEC (PCM) relay. Check pins 2 and 3 for key on battery voltage and pin 5 for power out and pin 1 for a ground at the relay.

Customer: replied 6 months ago.
have ground at pin 1, 12v at pin 3, nothing at pins 2 or 5
Expert:  Ron replied 6 months ago.

Pin #2 gets its power from the fuse F1-28 and if you sure the fuse is okay then you should have power at pin 2, with out power at pin 2 5 would be dead. Recheck the fuse and if it checks okay then you are likely looking at a bad fuse panel.

Customer: replied 6 months ago.
i have no power on either side of fuse 28
Expert:  Ron replied 6 months ago.

That would indicate a problem with the fuse panel as well. What happens if you supply power to this fuse?

Customer: replied 6 months ago.
the pcm relay energizes, but still will not start & no lights on dash
Expert:  Ron replied 6 months ago.

Okay do you have power at the coils on the power wire (green/red) ?

Do you have power at the injector on the red power wire?

Customer: replied 6 months ago.
i checked the relay & it is good, where do i find the red & green & red wires?
Expert:  Ron replied 6 months ago.

You can find the red power wire at any one of the injector connector and you can find the red/green wire at any one of the coils. Both are the power supply wires and the key needs to be on while testing.

Customer: replied 6 months ago.
12v at the injector & nothing on the coil, (won't crank over)
Expert:  Ron replied 6 months ago.

Okay if you look at the wiring diagram I sent you you will see that power to the coils comes from interior fuse panel from pin #7, do you have power out of the panel on pin #7 (red/green wire) ?

Customer: replied 6 months ago.
OK, I have to go to work, can I get back on here tomorrow?
Expert:  Ron replied 6 months ago.

Yes, Im here all day. Post back when your ready.