2000 KW W900L Starter Problems

Discussion in 'Heavy Duty Diesel Truck Mechanics Forum' started by Montanajon, Jul 5, 2021.

  1. Montanajon

    Montanajon Bobtail Member

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    I have a 2000 Kenworth W900L with a 12.7 Detroit. I was driving down the driveway and the truck just shut off, I figured I had a direct short somewhere, but all the wires were good. The solenoid was smoking a little, I was able to start the truck and get it back home, I kept looking for a shorted wire but could not find one. Is it possible the starter could have an internal short?
     
  2. Rideandrepair

    Rideandrepair Road Train Member

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    Loose connection more than likely. When it quit, if you lost the dash check engine lights, and buzzer. (Key on, before cranking test mode) Its likely the small ecm ground wire from battery to frame. Take them off, clean the ground wires and the frame. Also check the ecm supply wire from positive on battery , check it good, along with the small 5 amp inline fuse, it might be corroded. That’s IF the dash check engine lights quit working, when it died. Shows a lost ecm connection. Might have just lost connection enough to make it die, and then started working. And dash lights not working wasn’t noticed. Smoking starter, might just be a result of cranking with bad or loose connection. Might be on its way out, or just pulling a high draw when cranking due to a loose connection. Check all connections, starting at batteries. Cleaning everything up, especially the grounds to frame. Then make sure the starter wires are all tight, clean up the ground to frame. And the wire from starter to alternator, making sure it’s not chafed and grounding out. Any other grounds to frame you can find. Shorted battery will cause it to smoke, or jumping it with a shorted battery, loose connections, will cause the starter and batteries to smoke. Don’t think it will cause it to die though. To die, it’s usually the ecm ground wire, or positive wire, or the ecm fuse. Or a broken large cable to the Starter. That’s usually very obvious.
     
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  3. pavrom

    pavrom Road Train Member

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    Check for loose wires on the ignition lock
     
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  4. Montanajon

    Montanajon Bobtail Member

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    That is great info! Thank you very much. I will check all of the ground wires. I did pull the starter off and will be replacing it now. It looks pretty old anyway. I just bought the truck so I am trying to find everything going on with it. I also replaced the batteries, and cleaned the cables. Hopefully I can find a loose ground wire.
     
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  5. Montanajon

    Montanajon Bobtail Member

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    Thank you. I did check those wires and they are all tight.
     
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  6. AModelCat

    AModelCat Road Train Member

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    It shut off by itself while moving? That's not a starter problem.
     
  7. Last Call

    Last Call Road Train Member

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    What AModel said... did you even have the starter or batteries tested ???
    Or you just replaced them cause they looked old :biggrin_2559:
     
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  8. Montanajon

    Montanajon Bobtail Member

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    The batteries were tested, not the starter.
     
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  9. BoxCarKidd

    BoxCarKidd Road Train Member

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    It is possible the starter solenoid plate welded itself to the contacts. Usually caused by low voltage. When the starter, running constantly, draws the voltage low enough the engine will shut off. it would be very unusual for a starter to ever make another start if this happens. If you replace all that stuff many trucks also have a control relay. Wired in somewhere between the key or starter button and the starter solenoid. Replace that as well.
     
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  10. Montanajon

    Montanajon Bobtail Member

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    Thank you, when I was driving the truck home after I bought it, that solenoid that is located in the battery box actually melted, so I replaced that already. One of the batteries was bad at that time. So there is defiantly another issue somewhere. I will check all of the ground wires tomorrow and see if there is a loose one.
     
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