2005 Road King Classic won't start...keeps blowing fuel pump and ECM fuses

Discussion in 'Electrical' started by justscott, Mar 10, 2011.

  1. justscott

    justscott Member

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    The bike turns over but won't start. Whenever I turn on the run switch, the fuel pump fuse blows, when I replace the fuel pump fuse and turn on the run switch again the ECM fuse blows....the fuses seem to blow out in alternate order. Also, does anyone know where I can find the relays for the fuel pump and the ECM?
     
  2. Hoople

    Hoople Account Removed

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    The fuel pump fuse is a designated fuse for the fuel pump motor only. For that one 15 amp fuse to blow, you would have to have a serious current draw at the fuel pump motor. I would not be concerned with the ECM fuse or any relays at this moment because everything else is up-stream of the fuel pump fuse. I would start at the fuel pump and check it's current draw.

    If that 15 amp fuel pump fuel is blowing, there is not much it can be except a pinched wire touching ground or the pump motor is shot.

    Working without schematics can be risky.
     
  3. justscott

    justscott Member

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    If it's a problem with the fuel pump wiring or the pump motor itself, wouldn't it only blow the fuel pump fuse and not the ECM fuse? The fuel pump fuse doesn't blow every time....it alternates between the ECM fuse and the fuel pump fuse blowing.....also, if when I remove the ECM fuse and hit the run switch the fuel pump fuse will not blow.
     
  4. HDDon

    HDDon Experienced Member Contributor Retired Moderators

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    Hoople is really the man when it comes to electrical, but I'll throw my ring in the hat and suggest you look at and clean all the connectors using dielectric grease when reassembling. What is the ECM fuse rating?
     
  5. justscott

    justscott Member

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    The ECM fuse is 15 amps as well
     
  6. Hoople

    Hoople Account Removed

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    No, and the reason is because the fuses are in series. The ECM fuse supplies power to the system relay's normally open contacts. Those normally open contacts then supply power to the fuel pump fuse. The fuses are therefore essentially in series and each fuse is 15 amps so take your pick on which one will blow. But since the fuel pump fuse ONLY protects the fuel pump motor circuit and is DOWNSTREAM of the ECM relay & fuse, you must fix that issue 1st.
     
  7. justscott

    justscott Member

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    I see. Ok, I guess I'll look at the fuel pump first. Would it be possible that the system relay is bad and shorting out those fuses?
     
  8. Hoople

    Hoople Account Removed

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    Probably not. If the relay was bad, the things that would happen are:

    1) Fuel pump always runs and you can not turn it off using the "run" switch.
    2) Fuel pump never runs but the fuel pump fuse also NEVER blows.
    3) ONLY the ECM fuse keeps blowing, (never the fuel pump fuse).

    The only way the fuel pump fuse can blow is if device DOWNSTREAM of it is drawing too much current. The only thing down stream of that fuse is the pump.

    Remember I am not in front of the bike. When I say downstream, it's up to you to find a the pinched wire, shorted pump, wire touching ground, water filled connection etc etc..
    From here all I can say is your problem is downstream of the fuse. That sure does not leave you a lot it can be.
     
  9. justscott

    justscott Member

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    I was also told there was a fuel pump relay and an ECM relay. I am unable to find them if that is true. I've looked under the seat, and under the right cover. All I see as far as fuses and relays under the right cover are the 2 fuses (fuel pump, ECM), and the system relay. They are all located in the same fuse block.

    I was told that I could swap the brake relay, and the starter relay for the fuel pump relay and the ECM relay to see if the problem persists....I was told the problem may be with either the ECM, or fuel pump relays....is that worth even pursuing?
     
  10. Hoople

    Hoople Account Removed

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    Only way that could be a consideration is if the 2006 had a bunch of changes the 2005 does not have. I am using a set of 2006 schematics and your bike is an 2005 so changes could have taken place. But even if the 2006 is a bunch different than the 2005, I can't see HD hanging other devices off the fuel pump fuse. (possible but very remote)

    When you really look at what we both are doing, you really should not be working on your bike without the correct service manual and I really should not be giving advice to you without one either. But we are doing it anyway. I figured based on all the manuals I have read, I am 99% sure of what I am tell you is accurate.:)

    Now if you can upload a few pages from a 2005 manual, I could be 100% certain of what I tell you and tell you exactly what is wrong.