Electrical Nightmare

Discussion in 'Electrical' started by Trevornoyes66, Sep 25, 2018.

  1. Trevornoyes66

    Trevornoyes66 Member

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    My father in law was killed several years ago and my wife begged me to get his expedition. Prior to his death it had a little shake like bad coil packs. I finally agreed and brought it home. A new battery and some fresh gas I started it and drove it into the shop. All of a sudden it cut off like the key was switched off. Turning the key would turn it on but not crank. I found bad pcm fuse, and no ground on starter relay. I pull apart the junction box and find a bad spot and solder a 22 Gauge jumper in. Reassembled, still doesn’t crank. Anti theft does not blink fast, I can spin it over at relay with jumper 30/87a but no injector pulse. Will start on starting fluid. Please help, she is heartbroken and my knowledge is Chevrolet. Best I can figure is no ground from pcm at junction box.
     
  2. 1955moose

    1955moose Full Access Members

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    I think your overthinkin. Do the standard fuel pump pressure test. Check for power at enertia switch. It is possible you have a failed/failing fuel pump .

    Sent from my N9131 using Tapatalk
     
  3. Trevornoyes66

    Trevornoyes66 Member

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    Would that cause no start signal or injector pulse? It will not turn over with key. Pats light steady blinks no matter key position, no fast blink. I ohmed the switch and all positions read fine. The pump may be going bad I will check pressure, I just find it odd multiple issues happened at the same exact time
     
  4. stamp11127

    stamp11127 Super Moderator Staff Member

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    Sorry about the loss to your family. The starting circuits vary between the generations. Which year do you have?

    Mice can get into harnesses and wreck havock, so it is possible.
     
  5. Trevornoyes66

    Trevornoyes66 Member

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    It is a December of 2004. I traced the power to the neutral safety. Then checked back to the cjb and couldn’t find the pin. The hurricane just hit us so I’m trying to keep our minds off of the damage and focus on fixing this for her
     
  6. stamp11127

    stamp11127 Super Moderator Staff Member

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    I'll post the wiring diagrams tonight after work.
     
  7. 1955moose

    1955moose Full Access Members

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    No Injector pulse at injector plug is a break in wiring somewhere, or fuse. The injectors run through the pcm module. It sounds like you've got multiple issues. You should be able to jump the neutral switch if you've narrowed it down. Do you have power from the small wire that goes from ignition switch to starter solenoid on firewall? Do you have a 2005 wiring schematic. Stamp and the others are better at wiring than I, I'll hand it off to them.





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  8. stamp11127

    stamp11127 Super Moderator Staff Member

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    If that is still true the ignition system is functional. To pick up the injector pulse you need an oscilloscope or noid light. DMM's response time is too long for the pulse.

    I'll look at the diagrams after dinner tonight. If you need help reading the diagram just ask.
     

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    Last edited: Sep 25, 2018
  9. Trevornoyes66

    Trevornoyes66 Member

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    Well when I got home I went back to work on it. Newly charged battery and jumper cables just to insure no drain. I traced and pin 86 of start relay did have power, no ground is coming from pcm on blue orange. I checked at pcm and hooked a ground to this wire and it turned over fine. Fuel pressure is great, 38lbs and although the gas is a little stale it has 15 gallons of non ethanol added. Still will not start. Is this sounding like pcm? I did notice the oil pressure gauge doesn’t move during cranking, unsure if this is normal on fords. My Z71 shows pressure during crank. Sorry for prattling on
     
  10. Trevornoyes66

    Trevornoyes66 Member

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    I am having difficulty testing pcm circuits, all the pin outs I find are for different pcms. Mine has 3 plugs but they have vertical pins on the sides of each and horizontal in the middle. ID is damaged, all I can read is RPM2. I believe PCM is bad but I would feel better if I could insure it. I’m still curious why the ground pin on starter relay burned out and the 1.34 pcm fuse blew when it cut off
     

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