Blinker runing half speed?

Discussion in 'Generation 4 - Maintenance & Troubleshooting' started by 76FoMoCo, Jan 19, 2021.

  1. 76FoMoCo

    76FoMoCo SHO Member

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    I have checked all 4 and they all work but now only run under half speed? parts guy at ford was telling me there are a 4 things that can do this soooo not to the real experts.

    Thanks
    Shane.
     
  2. Ecoboost_xsport

    Ecoboost_xsport SHO Member

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    Probably running low....[​IMG]
     
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  3. ridered74

    ridered74 SHO Member

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    Check all of your running lights as well to make sure one isn't burnt out or not functioning.

    Every car I've ever had previously the turn signals would blink faster when one light was malfunctioning, but ford always likes to be different with their problems.

    If all other lights are working fine I'd suggest trading it in.
     
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  4. Johnbigdog

    Johnbigdog SHO Member

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    Becuase our car uses led lights in the rear, the body control module (BCMl cannot rely on monitoring amperage to determine if there is a lamp out for all four corners. For the front, yes. The rear no.

    The rear lamps are a module. The bcm sends power to the rear turn signal lamps to turn them on and off. The lamps have a feedback circuit that provide a corresponding voltage to the BCM to tell the BCM the turn signals are working. It is posible for a rear turn signal to work, but not send the verification signal back to the BCM to tell it the lamp is working.

    The BCM should set a D.T.C. for the feed back circuit if its not getting this signal.

    It is also posible that if you replaced the front turn signal lamps with LEDs they dont meet the load requirement and is now causing the BCM to think a bulb is out.
     
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  5. 76FoMoCo

    76FoMoCo SHO Member

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    Yes I was leaning toward the BCM. all stock bulbs and all working but it has shown a few odd things since the blinkers at half speed. It will also cycle the locks like you hit the unlock button just out of random. It will also honk and show a turn signal for a split second now and then.
    I'm wondering if the BCM needs to be replaced and if so will it mess up my tune? or is the PCM not tied in this way? I have had this car new and it now has 77K on it.
    Thanks for your input.
     
  6. Johnbigdog

    Johnbigdog SHO Member

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    The bcm will not affect your tune.

    The bcm is likely not at fault unless you have a water leak. You can see it. Its the fuse box under the dash on the drivers side.

    I would put more money on a circuit fault.
     
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  7. robert francis

    robert francis New Member

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    Bad and or corroded "grounds" can often cause poor circuit actions.
     

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