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Glow plug control module

Discussion in '6.9L IH & 7.3L IDI Diesels' started by notenuftime, May 13, 2019.

  1. notenuftime

    notenuftime Full Access Member

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    Recently replaced my glow plug module, before I replaced it I could hear a buzzing type noise when the GP where heating. Now with this new one it makes no noise, the wait to start light comes on and i can see the Amps moving after. Truck starts fine hasn't been cold, started it this morning was in the 40s. I'm just wondering if i should be hearing a noise when the GP are heating or may something be wrong. GP are around two years old.
     
  2. riphip

    riphip Supporting Member Supporting Member

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    I hear no noise with mine. May have been old GPC solenoid buzzing not making good contact upon initialization.
     
  3. notenuftime

    notenuftime Full Access Member

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    Ok, i thought the same.
    Figure i would inquire.
     
  4. BeastMaster

    BeastMaster Registered User

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    Mine turns full ON for maybe 10 seconds or so, followed by several bursts at around 1 second intervals, then OFF.

    The wait to start light goes OFF at about the same time the cycling starts.

    When I first bought the beast, I thought all the voltage fluctuations upon startup were indicative of bad wiring, but now, knowing how the glow plug circuit works, I find this to be very helpful to my assessing battery and glow plug health upon startup.

    I would be quite concerned about buzzing sounds. I can see no reason for switching glow plugs like that, as well as being really bad for the relay contacts.

    My hat is off to the designers of my beast... I am very impressed with the design elegance I see. If I had to choose an animal to represent my beast, it would be either an ox or a hippopotamus.
     
  5. IDIBRONCO

    IDIBRONCO IDIBRONCO

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    I think that I may have heard this same sound before. It's hard to describe, but I wouldn't strictly call it a buzz. I would say that it's kind of a combination buzz/whine that goes up in pitch.
     
  6. notenuftime

    notenuftime Full Access Member

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    Yes this is what i heard.
     
  7. IDIBRONCO

    IDIBRONCO IDIBRONCO

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    I have no clue as to what it may have been. It was on customer's trucks. They started fine and had only been in for an engine. There were no complaints about it so they must have been making the sound before they came to us and kept starting afterwards. Is it a bad sound? No idea. I've only heard it with the 7.3 style controller, never the 6.9. It is strangee though.
     
  8. notenuftime

    notenuftime Full Access Member

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    It had sounded that way since i bought it back in 2015, started it a couple times in -10 degree weather. Not having that noise doesn't seem to be a issue.....weird.
     
  9. FrozenMerc

    FrozenMerc Registered User

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    The noise came form the old analog electronics that had moving parts (relays) built into the factory original ones. The new aftermarket replacements use solid state electronics with integrated circuits to achieve the same functionality. No moving parts = no noise. The now circuitry is much cheaper and easier to produce. Electronics have change a whole bunch since the early 90's.
     
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  10. Thewespaul

    Thewespaul Supporting Vendor Supporting Member

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    The factory ones are solid state controlled on all the 7.3s and late 6.9s, if you look back into the sales brochures for the bricknose trucks it’s one of the features ford really pushed, that the glow plug control was now performed by a “state of the art” solid state controller.
     
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  11. snicklas

    snicklas 6.0 and Loving It!! Staff Member

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    The glow plug relay has “whined” not really a buzz, on all my IDI’s. Even a couple replacements did.
     
  12. FrozenMerc

    FrozenMerc Registered User

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    Interesting. I haven't graduated to the newer Bricknose trucks yet. I am still playing with a Bullnose....
     
  13. Agnem

    Agnem Using the Force! Staff Member Supporting Member

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    Some make the noise and some don't. The current rushing through whatever it is, seems to cause the noise. It's harmless, and actually if it makes it, be happy. It's easier to tell when its not working.
     

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