My fuel pump is not grounding properly

Discussion in 'Electrical' started by sincityharley, Sep 20, 2010.

  1. sincityharley

    sincityharley Member

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    My bike recently quit working. I spent an entire weekend trying to pin point the problem. What I have come up with is that the fuel pump is not grounded properly. When I apply direct current to the fuel pump tabs it will start. If I jumper a wire from the frame to that chrome bolt on top of the speedomoter guage that holds the speedomoter/electrical panel in place, the bike will start! With the jumper wire removed the bike will start some of the times. It will also die while at speed sometimes. If I let the bike sit for about 10 minutes after it dies it will usually start again. Obvioulsy there is a ground issue. Where does my tank get grounded to the frame? How can my tank be grounded sometimes and not others? What does waiting 10 minutes have to do with why it would start again? Has anyone had this issue before? Also in case it matters I have my fuel guage unplugged as I origianlly thought that was causing my issues. Im super confused. Any advice would be much appreciated. Thanks
     
  2. dcfatboy

    dcfatboy Active Member

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    How are your battery ground connections?
     
  3. Jack Klarich

    Jack Klarich Expert Member

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    You can check the tank ground with a test light hooked to the positive post of the battery, careful touch the tank mount bolts with the other end of test light, if you have a ground the test light will light up, hope this helps:s
     
  4. Hoople

    Hoople Account Removed

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    The tank may or may not be grounded to the frame because it does not need to be. That is because the Tank itself is Not used to ground the fuel pump. The wiring harness has a dedicated wire that is used for the electrical return path for the pump. The pump does not even have to be touching the frame of the bike for it to operate.

    I can not speak for your 2002, but on my 2009 the fuel pump is grounded using a ring terminal Grounding stud which is under my seat. There are two studs under the seat (2009) that are used for a "star" or "wagon wheel" grounding configuration.

    You need to refer to a service manual for your exact year. It will be very clear exactly where to look. My wagon wheel grounds happen to be under the seat. Most likely yours are the same or somewhat close...
     
  5. Hoople

    Hoople Account Removed

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    Steve, our pumps are safety wired. But they don't use the oil pressure method. Instead the ECM looks at the crank sensor output and stops the fuel pump if the crank trigger is missing. The fuel pump is first turned on by the ECM for two seconds (to pressurize the system for start up), then the ECM turns the pump off and waits for a crank trigger signal to continue to run the pump. The BAS also comes into play by killing the engine on tip over.

    (how it applies to my 2009. Others may be different)
     
  6. Hoople

    Hoople Account Removed

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    Your right Steve, that 10 minute wait period is strange. It's just so hard to say without seeing a schematic for that exact bike.