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Won't stay charged

Discussion in 'Ford Trucks' started by TopNotchLS, Nov 28, 2006.

  1. TopNotchLS

    TopNotchLS Junior Member
    Messages: 4

    I have a 91 F-350 and with or without the plow on it, it won't stay charged. I've changed the battery and alternator. Does any one have any ideas. Thanks a lot.
  2. grandview

    grandview PlowSite Fanatic
    Messages: 14,609

    Have you checked the fuses?
  3. MickiRig1

    MickiRig1 PlowSite Veteran
    Messages: 3,617

    Are you sure the alternator is actually working? You may have a popped fusible link or a broken / fried wire or a bad connection somewhere.
  4. SnoFarmer

    SnoFarmer PlowSite Fanatic
    from N,E. MN
    Messages: 7,921

    Do and check all of the things mentioned.above.
    Then start to look for a short or power draw.
    turn the key to off.
    disconnect the pos from your battery,
    pull the fuse for the radio.
    Then cheek for voltage between the pos post and the pos cable.
    The reading should be 0 volts.

    if you have any voltage you can do it two ways start pulling fuses until the voltage drops to 0 when the voltage drops that is your power draw.

    or pull all of the fuses and start to push them back in and when the voltage goes up you have the circuit that is at fault.
  5. TopNotchLS

    TopNotchLS Junior Member
    Messages: 4

    thanks a lot I'll start trying these things in the next few days.
  6. MickiRig1

    MickiRig1 PlowSite Veteran
    Messages: 3,617

    If you have a Volt Ohm Meter check the system. It should be 12.5 -> 12.6 Volts not running. When running it should be 13.5 -> 14.5 Volts. When running the plow etc it will drop below 12.5 that's normal for the load involved. Most auto parts stores will test your system for free. Even Mom and Pop places will do it. They hope to sell you parts. Charge the battery / batteries and have it tested.
  7. wilfred17

    wilfred17 Junior Member
    Messages: 4

    This might sound stupid, but check the battery light on the dash when the key is on. On my 89 f-250 it was needed to excite the field on the alternator. I went through 5 alternators before discovering the bulb worked out of the socket(from me beating on the dash)
  8. MickiRig1

    MickiRig1 PlowSite Veteran
    Messages: 3,617

    On My 89:
    I went over some railroad tracks and my light came on. I tested the system and the alternator was not working. I pulled it off and took it apart. The Little copper field wire had broke.