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  1. #1
    Join Date
    May 2010
    Posts
    16

    Default hooked up the battery backwards :(

    Well long story short, never trust the little red throw away cap. My new battery had the red cap on the negative. anyways I tried starting the engine before figuring it out. After switching the cables, to my surprise she fired right up but the alternator seems fried and the stereo won't turn on


    Anyone know if there are fuses for these that aren't under the dash , I already checked those, that I need to check before taking the alternator out and replacing the radio?

    2006 supra 20ssv with 325 indmar assault


    Thanks

    Travis

  2. #2
    Join Date
    May 2006
    Location
    Nashville
    Posts
    2,127

    Default

    Normally the starter solenoid will cook before the alternator. I'm assuming it was a quick pop, and then you undid the cables?
    When the engine is running put a voltmeter on the line from the alternator, you want to be getting at least 12-13volts. 14+ is optimum.
    What makes you think your alternator is toast? Is the voltmeter not registering? Could be a fuse in the dash array setup keeping the gauge from working. Test the alternator first with a volt meter, and then work down the line.

    As for the stereo, check the back of the head unit. Typically there is a fuse on the back.

    Don't feel bad, I did that once in my CJ by not paying attention. Zaaaaaaaaaaaaap, and some smoke from the starter solenoid. Amazing it started up and ran fine. But the fuse on the back of the head unit was toast.

  3. #3
    Join Date
    May 2010
    Posts
    16

    Default

    Quote Originally Posted by haugy View Post
    Normally the starter solenoid will cook before the alternator. I'm assuming it was a quick pop, and then you undid the cables?
    When the engine is running put a voltmeter on the line from the alternator, you want to be getting at least 12-13volts. 14+ is optimum.
    What makes you think your alternator is toast? Is the voltmeter not registering? Could be a fuse in the dash array setup keeping the gauge from working. Test the alternator first with a volt meter, and then work down the line.

    As for the stereo, check the back of the head unit. Typically there is a fuse on the back.

    Don't feel bad, I did that once in my CJ by not paying attention. Zaaaaaaaaaaaaap, and some smoke from the starter solenoid. Amazing it started up and ran fine. But the fuse on the back of the head unit was toast.
    It actually never sparked when I hooked it up backwards so I didn't notice until after I tried to start it and all I heard was a spinning noise like the starter wasn't engaging. I figured the new battery wasn't fully charged so I went to hook up some jumper cables and noticed then. If I remember correctly the altenator was putting out about 14 on the dial last year but when I started it after reversing the cables it never budged past 12, but I'll definitely give it another shot and rev it up a little to make sure it's done for before pulling it.

    I'll look for that fuse on the back of the head unit. Thanks for the tip

  4. #4
    Join Date
    May 2010
    Posts
    16

    Default

    Found the fuse in the back of the head unit, fixed everything up! The alternator is getting the diodes replaced and should be good to go by tomorrow. Overall not nearly as bad as I had expected, ~$80 mistake and a few hours

  5. #5
    Join Date
    May 2006
    Location
    Nashville
    Posts
    2,127

    Default

    That's good to hear. Could have been way worse, I know fires that have started that way.

  6. #6
    Join Date
    Feb 2009
    Location
    Central, AR
    Posts
    58

    Default

    Glad things wrong out. That could have been a expense life leesson.

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