Bronco solenoid problem

Discussion in 'Shop Talk' started by Haynes, Mar 20, 2005.

  1. Haynes

    Haynes Well-Known Member

    Jan 22, 2005
    S W Va.
    The solenoid on the Bronco locks down and then keeps the starter spinning
    till I can break the battery connection. 3 starters, 3 solenoids and a new
    ignition switch no help.The local Ford place could probably fix it but I
    got ****ed at them when they claimed it was cheap aftermarket solenoids
    and I paid them double for genuine Ford and it went a day before locking
    and its just like the other ones. I can hotwire it to start it and it never does it.
    With the price of gas, I'm not wearing it out 4 wheeling anyway.
    When you tear the solenoid apart, the contacts are arced together.
    It's an 89 full size 4 x 4.
    Any ideas.

  2. Beeman

    Beeman Well-Known Member

    Dec 28, 2002
    East TN
    Possibly bad ground cable or pos cable causing high resistance in the circuit. Use a volt meter and measure voltage dropas across each section of the system when cranking.

  3. moopups

    moopups In Remembrance

    May 12, 2002
    In beautiful downtown Sticks, near Belleview, Fl.
    The ignition switch is sticking causeing the solenoid to stay engagued, again only an opinion. Its age seems to be about right for this to happen. Rereading I see you changed the switch; its now sounding like a ground issue. Could be a short in the wire that comes from the switch to the solenoid. If its gaining currant elsewhere that could be the source of the problem.
  4. John Hill

    John Hill Grand Master

    May 12, 2002
    New Zealand
    If the Bronco is anything like the Ford I have there are a number of components in the circuit between the solenoid and the ignition switch. There is a relay, the body control module (computer thing), immobiliser (another computer thing) and the engine control unit (yet another computer thing) plus the transmission interlock switch. It would seem that any of these could be causing the problem but I would be especially suspicious of the relay.

    You did say that 'hot wiring' is reliable so if you are unable to get anyone who can properly fault find the circuit you might consider fitting a push button starter switch.
  5. herefordman

    herefordman Well-Known Member

    Aug 24, 2004
    washington/british columbia
    The solenoid is hooked up backwards, you have the battery cable, and starter cable on the wrong sides. :)
  6. Herb.

    Herb. Well-Known Member

    May 10, 2002
    Layton, Utah-for now
    Take the small wire off of the solenoid when the starter sticks, if the starter disengages repeat the process untile you are sure this is the cause, if it is, there is voltage on that wire when there is not supposed to be. If this makes no difference check the battery voltage with the engine running, should not be more then about 13.5-14, if this is ok, visually check the heavy wire that runs from the solenoid to the starter. Sounds like it is pulling too much amperage or pulling it for too long a time causing the contacts to weld together.
    Since it seems to work when you hot-wire it I would suspect there is voltage on the starter engage wire on the solenoid after the key is released, since you have replaced the ignition switch it must be coming from somewhere else.