How do I wire gm alt to 1981 Toyota pickup?

Discussion in 'Interior/Electronics' started by Ryan99, Mar 20, 2021.

  1. Ryan99

    Ryan99 Newbie

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    Location:
    Sacramento
    Truck:
    81 yota pickup
    Ok I’m sick of the shitty charging system that came from factory. My charge lights flicker all the time but I have 12.8-13.3 volts. Swear if I touch the voltage regulator it will start to click and charge light will intermittently flash. If I turn on the headlight it will stop but come on randomly.
    literally started to happen after I cleaned terminals. I’m done and just want that clicking to stop and charging back at 14+volts . I’m stumped on what I should check next. I checked the fusible links on the battery terminal and rewired them and it made the problem even worse.

    So here’s my dilemma should I run a gm alternator? If so what kind of wiring is involved and do you think it will solve my issue? I’ve been reading about 1 wire and 3 wire and not sure which one I should pick. What’s the price and parts that I need? I work at Autozone so it shouldn’t be that hard to get.

    I’ve been reading around and something about 2 wires from the voltage reg and 1 to battery? Could those 2 factory wiring also present an issue or will it cure this carvid19
    Disease.

    specs: new 6 wire voltage regulator, shitty new 40amp alty. Also 2-10s subs with a 1000w Sony which is absolutely trash with factory power system. And a eBay digital volt meter soldered to the keyed ignition (thick red wire) and grounded.

    Any info on wiring and parts I should get would be greatly appreciated!
     
  2. fred heath

    fred heath Addict

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    You’ve got bigger wiring problems than just your alternator. 40 amp is way too small especially considering all the stereo components you’ve installed.
    You might want to consider a separate battery tied into an isolator for your stereo components. Upgrading to a GM might help some, but your asking a lot from a single battery.
    Before going crazy with upgrades temporarily disconnect all stereo components from your system. See if your charging issues go away. A good, well charged battery is a must.
     
    Last edited: Mar 20, 2021
  3. TRUCK ACTION

    TRUCK ACTION Grand Toyotaholic

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    I run a GM 12SI alternator from Quality Power, they also supplied a harness that allowed straight plug in to my connectors. The unit I got is polished billet cased, 100 amps at idle & 160 at 2,000rmp.
    I had already upgraded the wires to the alternator, & I run a Odyssey PC1500 DT ./34/78 battery.
    I have a 1,000 watt stereo set up, electric fan , & air ride with 2 Viair 485 compressors.
    This has proven to work well on my 88 Extra Cab
     
  4. jetas

    jetas Grand Toyotaholic

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    :ROFL::ROFL:Waaaaay too much draw for only 40A alt. I can bet the amp you have has atleast a 30A fuse or multiples. That alone will suck all the juice from the alt instantly if you have it turned up.

    I have a 100A GM alt that i already need to upgrade because of my amp and air compressors. As soon as my comps come on my voltage drops to almost 12.5 at idle.
     

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