Electrical Help Installing Amp

Discussion in 'SN95 4.6L Mustang Tech' started by roadman4.6, Dec 14, 2012.


  1. roadman4.6

    roadman4.6 Member

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    Tried to install my new amp tonight in a hurry and forgot to disconnect the battery. Small spark when I connected the ground wire and now car won't start. Everything is dead - no lights inside or out, won't crank at all. All worked before I started. This amp/sub was wired before and working fine, just replaced the amp. Did I blow a fuse or fry something major? Stupid mistake - hope it is something easy.
  2. wmburns

    wmburns SN Certified Technician

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    If everything is dead including the headlights, then the problem HAS to be between the battery and the battery junction box.

    Confirm the battery voltage with a real volt-ohm meter.

    Check the white fusible link in the main battery cable. There should be +12 volts at the main B+ alternator terminal with the key off.

    Confirm the negative battery terminal is clean and tight as it is bad about splitting when tightened.

    Confirm that the main battery cable is connected, clean, and tight at the BJB.

    Confirm there is +12 volts to the input side of the fuses in the BJB.
    kramer likes this.


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  3. Mattstang04

    Mattstang04 Active Member

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    I have this problem with my truck sometimes. The negative terminal likes to lose contact. The terminal will be tight on the post but due to some build up or moisture it needs to be cleaned and reconnected or it wont ground. I'll get in, the dome light will come on, turn the key, and whole truck goes dead. Hopefully yours is nothing major.
  4. roadman4.6

    roadman4.6 Member

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    Thanks - split battery terminal and ground was loose. Pulled battery anyway and it checked OK. Will buy new terminal tomorrow and hopefully everything works again.

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