2001 Expedition ,no power to coils

Discussion in 'Explorers - Expeditions - Excursions - Broncos -Es' started by 1935 Ford, Jan 5, 2019.

  1. 1935 Ford

    1935 Ford Junior Member

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    I just did head gaskets on my 2001 Expedition with a 4.6 because of a bad oil leak ,now i have now power to the red with green side of the coils . When i put the batery back in and hooked it up the gauges went nuts . It fired once like it was flooded then after that nothing ,it just spins and the coils are dead . I checked fuses and they show good ...any ideas what i may have missed?
     
  2. Leo_Leo28a

    Leo_Leo28a Junior Member

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    Did u check your head/block ground connections. ?


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  3. 1935 Ford

    1935 Ford Junior Member

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    Yes ,they are in place . Just no power to the red with gren wire to coils when the key in in the on run position . I did a new crank position sensor but no change
     
  4. Leo_Leo28a

    Leo_Leo28a Junior Member

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    If all ignition-related fuses checked out ok, including fuel pump circuit, then you must have an open in the harness hot wire. And you need to chase that open with an ohm meter or test light.

    But before you trace the open in harness, just make sure you do have power coming out of ignition switch.
    That's the only source of power to coils in run position.




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  5. 1935 Ford

    1935 Ford Junior Member

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    Yeah ,injectors are working and it looks like everything else is working ,just the power to the coils . When i put the bsttery in agter i got it back together the gauges went crazy ,the battery had a full charge . It did hit one time then nothing ,after testing i saw the coil power was dead . Unpluged everything and pluged it back and still nothing . I am wondering if it may have fried the computer
     
  6. Leo_Leo28a

    Leo_Leo28a Junior Member

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    No way
    Like i said Coil power feed is supplied direct by ignition switch circuit.

    All you need is a test light to verify the feed circuit.


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  7. 1935 Ford

    1935 Ford Junior Member

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    I did a test and found the wire is good from the coil to the plug in but no power at the oppsite side of the plug in ,this is the plug in below the computer block ,the coils do not run through the computer block , they run through the smaller plug in below so i am sure you are right and the coils power come from the key. Cant figure this out ,the fuses are good and have power at both sides when in place . This should have been the simplist part ,it all just plugs in and everything worked before i did the head gaskets . It has to be some where between the key and the plug in in the engine harness. Is it possible to jump this connection just to see if it will start?
     
  8. Roush PSD Interceptor

    Roush PSD Interceptor 7.3L Straight Piped Diesel

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    @1935 Ford

    Since it is "supplied direct by ignition switch" ?
    (gray with yellow trace)
    ( I doubt it just comes from the master switch
    to the coils without a relay or fuse inline)
    jumping this connection will give the coils power.

    The important thing is that you find out where
    the break in the wiring has occurred.

    This diagram shows the power comes from the
    Central Junction Box. In turn the CJB is energized
    by the run wire from the ignition through a relay
    or fuse.

    2001 Expedition.jpeg
     
    Last edited: Jan 8, 2019
  9. Roush PSD Interceptor

    Roush PSD Interceptor 7.3L Straight Piped Diesel

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    Have you tried testing the ignition relay ?

    Swap another non-engine essential relay
    (blower motor) into it's position and try starting.

    I pretty sure something energizes the "Hot/Run"
    pins (13-16) on the Central Junction Box besides
    just the fused wire coming from the Master Switch
    on the steering column.
     
  10. 1935 Ford

    1935 Ford Junior Member

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    Didnt try the relay ,i have a few here i can try
     

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