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XJ550 starter relay?

Discussion in 'XJ Technical Chat' started by Wirehairs, Jun 19, 2021.

  1. Wirehairs

    Wirehairs Member

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    I went to start my 1982 XJ550 seca yesterday, and it cranked like crazy... seemed faster than normal actually. When it didn't start after a few seconds, I let go of the starter button but it kept cranking. I turned off the ignition, but it still kept cranking, until, finally, it wore down the battery.

    Am I correct in saying I need to replace the starter relay?

    Thanks for any input!
     
  2. Minimutly

    Minimutly Well-Known Member

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    Starter relay / solenoid, whatever you want to call it - yes.
     
  3. XJ550H

    XJ550H Well-Known Member Premium Member

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    measure the studs with a meter see if the solinoid welded shut.
    also ohm/continuity check out the blue white wire that runs from solinoid connector to the starter button to ground it may have stuck on you.
     
  4. Minimutly

    Minimutly Well-Known Member

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    Why? Surely with ignition off there is no feed to the start button? ( not familiar with the 550 so apologies if this is wrong).
     
  5. XJ550H

    XJ550H Well-Known Member Premium Member

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    the test is to the starter button from the connector for continuity.
    from 2 pin connector blue/white wire
    if button is stuck you will get continuity to ground through the starter button. pressing starter button makes the circuit to ground.
    if button is not stuck you will get no continuity untill you press button.

    with key on you can test for voltage on the red/white wire at the 2 pin solinoid wire

    on the solinoid studs you check continuity from stud to stud. it should read open , no continuity. if contacts are welded shut you will get continuity.

    what was discribed by poster was starter kept running so
    1 starter button stuck
    2 contacts in solinoid stuck /welded t gether.
    3 issue involves diode block
     
  6. Minimutly

    Minimutly Well-Known Member

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    with key on you can test for voltage on the red/white wire at the 2 pin solinoid wire

    So, no power on the red/white at the solenoid, the only way the solenoid can stay closed is if it's welded?

    Why would you go through all the rigmarole above if the op said it stayed on after switching off?
     
  7. XJ550H

    XJ550H Well-Known Member Premium Member

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    I have had the diode block fail and keep the motor spinning over. It could be his starter button was stuck. Just want him to check everything out before he buys him and solenoid.
     
  8. Minimutly

    Minimutly Well-Known Member

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    That's really interesting - do you recall was this an earthing (as in shorting out the button) or a constant supply and a faulty button?
    The second sounds unlikely, so I guess the diode block could provide an earth path. Will check out my diagrams. There would still need to be a supply on the solenoid +ve though..
     
  9. XJ550H

    XJ550H Well-Known Member Premium Member

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    bad diode in the block
     

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