Voltage Regulator Alternator Output ????

Discussion in 'Audio + Electronics' started by bugdewde, Aug 15, 2019.

  1. bugdewde

    bugdewde I'm Awesome

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    '95 K2500 454 TBI Suburban

    Suspect low charging ....

    Tonight, I was rolling down the road with headlights on high. I noticed the volt meter was well below 14, near 11.5. With high beams on and AC on max, volt meter down to 11.

    0815192126c.jpg

    I felt it should have been much higher (near 14), but question the accuracy of the gauge.
    I want to test the alternator output with my multimeter.
    Where is the best place to test output, at alternator or battery?
    What numbers are acceptable at idle?
    With revs?

    Also, is the regulator in the alternator like older GM alternators or in the computer?

    Any help for a newbie with his first gmt400 alternator/regulator question?
     
  2. Supercharged111

    Supercharged111 I'm Awesome

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    I've always checked at the battery, alternator will feed the battery. I want to say these trucks run around 13.5V when the battery is happy. I know my electric fan really puts a hurting on my stock alternator, I should upgrade to that fancy alternator like you have in your Burb. Regulator is on the alternator, same as all these trucks. I know 98+ had a measure of PCM control, but the regulator and rectifier was still on the alternator.
     
  3. bugdewde

    bugdewde I'm Awesome

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    13.5 at the battery. Thanks.

    Maybe I'm just paranoid since my only other GMT 400 experience is my '99 6.5L Turbo Diesel. Dual batteries and the volt meter never even flinched with both A/Cs, high beams & wipers on .....
     

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