Alternator Question

Discussion in '1996 - 2004 SN95 Mustang -General/Talk-' started by m0squ1t0, Oct 20, 2013.


  1. m0squ1t0

    m0squ1t0 Member

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    My 2002 Gt is not keeping charge due to my steeda UDPs. I was told I need a higher amp alternator to compensate. What size is stock? What size do I need? I don't have anything crazy in my car, no amps subs etc... Thanks!!
     
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  2. m0squ1t0

    m0squ1t0 Member

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    Anyone? I really need some direction...I have found out that the stock alternator is 110 amps so I need to know what size to replace it with to avoid having the battery drain on me.
     
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  3. COramprat

    COramprat Drone Driver
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    The PA alternator are 130 amps. What specific issues are you having now?
     
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  4. 99Blownstang

    99Blownstang Member

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    My opinion is that under drive pulleys are a joke. I have ran them and they just cause overheating problems
     
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  5. Mattstang04

    Mattstang04 Active Member

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    Has the alternator been tested to ensure that it is operating correctly? Could just be a case of an alternator going bad.
     
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  6. m0squ1t0

    m0squ1t0 Member

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    the battery and the alternator have both been tested. I was told both are good. I was also informed that the underdrive pulleys are causing the alternator to not properly charge the battery enough because if I sit at a red light while its raining with my radio, lights and windshield wipers on the battery gauge drops unless I rev my engine in neutral. I don't have anything crazy in my car I have a replacement deck with the factory equivalent speakers.I've never had any overheating problems.
     
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  7. Mattstang04

    Mattstang04 Active Member

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    Maybe try putting the stock pulleys back on and see if that fixes it. If it does, I would weigh the advantages of underdriven pulleys versus having to fix the issue. I had pulleys before my blower install. I was not impressed by any change they made.
     
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  8. m0squ1t0

    m0squ1t0 Member

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    Stock pullies are a no go. Car came with the UDP system.. This is a problem that is new not something that has been around...could this be a programming issue?
     
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  9. COramprat

    COramprat Drone Driver
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    While the alt and battery my have tested OK I'm betting they are at the minimums. I had UD pullies on my old car and had frequent power issues. I eventually did away with them.
     
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  10. m0squ1t0

    m0squ1t0 Member

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    I don't have thoriginal pullies, so for now thats a no go. Could i go with a higher amp alternator?
     
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  11. Mustang5L5

    Mustang5L5 Car used in adult film "Highway Gangbang-InDaButt"
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    Higher amp alternators are not the cure because they still require a minimum RPM in order to create power.

    The issue here is that your current alternator is spinning too slowly to produce a proper charge. Going to a higher amp alternator may not fix the issue of your accessory belt is still spinning too slowly to fix that issue.

    You have 2 solutions:

    1) find a set of stock pulleys and swap them back on

    2) Find a stock alt pulley, or an aftermarket alt pulley that will fit of larger diameter in order to OVERDRIVE the alternator and compensate for the slowed down accessory system.

    A 3rd option is to find an aftermarket alternator that produces full power at a lower RPM than stock. You'd need to know crank pulley size and alt pulley size and do a little bit of math to calculate if this will work.

    Option 1 is prob the easiest
     
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