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What are some good high amp alternator options???

Discussion in 'The Garage' started by dawson444, Feb 5, 2004.

  1. dawson444

    dawson444 1/2 ton status

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    What are some good options for a high amp alternator, such as after market or ones off of a different car/truck that will work. What mods are needed to make it fit? Thanks!
     
  2. Tweetysuarus

    Tweetysuarus 1/2 ton status

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    I used a 2003 Chevy Silverado 130 amp alt. & brackets on my 76 K5!
    Bill
     
  3. Burt4x4

    Burt4x4 3/4 ton status

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  4. rjfguitar

    rjfguitar 3/4 ton status GMOTM Winner

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    A cheap solution is to find an altenator out of a chevy delivery truck or cadi. They have a big case 100 amper usually. I just bought a rebuilt 100 amp cadi alt. the other day and my system was noticeably louder after I installed it. /forums/images/graemlins/thumb.gif
     
  5. j20m715

    j20m715 1/2 ton status

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    I am using a 145 amp from an 03 yukon. /forums/images/graemlins/thumb.gif
     
  6. BadDog

    BadDog SOL Staff Member Super Moderator Author

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    Mine's a 135A from an 89 sub with towing/camping package.
     
  7. Thumper

    Thumper 1/2 ton status

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    Do any of these options plug directly into the existing system thats in an 85 k5? Or are they all that new style that you need the wire adapter/ bracket mods to do?

    Mike
     
  8. az-k5

    az-k5 1/2 ton status

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    I'm running a 140A out of a pontiac transport (lifetime warranty). I had to buy a pigtail ($7) and splice it in. Works great except most hi-amp systems are also hi-rev. Just get the smallest pulley you can find to help it out. This alternator is a little bigger than stock. I lossened up all of the bolts on the bracket and shoved it in. It fit (to my surprise). I am sure the bracket is a little tweaked in there but I am not cooking or throwing belts and I have had it on for a month and ran the truck at 3000RPM for about an hour. I like the mod a lot.
     
  9. rjfguitar

    rjfguitar 3/4 ton status GMOTM Winner

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    [ QUOTE ]
    Do any of these options plug directly into the existing system thats in an 85 k5? Or are they all that new style that you need the wire adapter/ bracket mods to do?

    Mike

    [/ QUOTE ]
    The option I mentioned bolts directly in.
     
  10. big d

    big d 1/2 ton status

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    what year of cadi amp ? thanks. /forums/images/graemlins/thumb.gif /forums/images/graemlins/k5.gif /forums/images/graemlins/usaflag.gif
     
  11. rjfguitar

    rjfguitar 3/4 ton status GMOTM Winner

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    You will have to just look at the alt and see if it will work. They all aren't the same.
    I just bought mine rebuilt from a local guy that does alts, rads, and starters. He didn't really tell me the year mine is. /forums/images/graemlins/dunno.gif
     
  12. brake shoe

    brake shoe Newbie

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    cadillac: 92-95 maybe even earlier, check for the unit that has heated seats and heated window, this unit is the 145 amp unit, if you take it to a rebuilder, this unit is the cs144, change out the regulator to a 411 and change out the stator to a 21SI 165amp unit, the rotors are the same, your unit will now punch 165 amps around 2000 engine rpm's. If you set at an idle for a long time like a fire rescue truck, instead of installing the 411 regulator, install the 408 regulator, the 411 is temperature compensated, which means as the regulator heats up, the amperage drops off, the 408 regulator is not temperature compensated, which means instaed of pushing 14.8 volts like the 411, it pushes 14 volts constant, reguardless of the temperature, The regulator in the original Caddy needs to be changed out, the 408 and the 411 regulator will hook right up to your plug assembly without any changeover, but you will have to change the battery output cable size to something like 1 guage or bigger. Building this unit will give you about 95 amps at an idle, It is extremely hard to beat O.E.M. at there game for performance in alternator power at an idle, aftermarket units die at an idle, but can pound power at high rpm.
    Brake shoe (electrical rebuilder)
     
  13. BurbinOR

    BurbinOR 3/4 ton status

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    Couple more options -

    Have a local alternator shop build you up a 130+ amp one.

    www.wranglernw.com - I ran one of their direct charge 135 amp versions for over 5 years in my K5. Loved it, never a problem. Not cheap tho........ /forums/images/graemlins/yikes.gif
     
  14. Z3PR

    Z3PR Banned

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    Best high amp alternator option in my opinion would be to take it to a local shop that rebuilds alternators and have them build your alternator into a high output unit. /forums/images/graemlins/deal.gif
     
  15. rjfguitar

    rjfguitar 3/4 ton status GMOTM Winner

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    [ QUOTE ]
    Best high amp alternator option in my opinion would be to take it to a local shop that rebuilds alternators and have them build your alternator into a high output unit. /forums/images/graemlins/deal.gif

    [/ QUOTE ]
    I was going to do the same thing but... There is one small problem. We all have the small housing altenators that don't like to take a lot of heat over an extended period of time. The later(or commercial) larger housing alts can ahndle more heat for longer periods of time because thats what they were designed to do. It is cheaper just to have the bigger one rebuilt and use that.
     
  16. Blue85

    Blue85 Troll Premium Member

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    How about doubling the current delivery at all rpms for about $40?

    A high output alternator can be expensive. Stock ones are cheap. 2 stock ones = high current + low price.

    Here's what I did: [​IMG]

    Since this picture, I changed the brackets around so that both alternators are on the same belt. That front pulley on the waterpump is smaller, so the second alternator was turning slower.

    This system also offers redundancy, so an alternator can fail, without leaving you stranded. Plus, a replacement is cheap and always easy to find.

    The downside(?): No more A.I.R. pump
     
  17. 88K5Jimmy

    88K5Jimmy 1/2 ton status

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    Did you notice any differences in power output? Also, was the second alternator turning slower on the smaller pulley that big of a deal? For just a little better power output, seems like you could keep the second alternator on the smaller pulley just to up the voltage a little. Also, how did you wire that all in?

    Nice job /forums/images/graemlins/woot.gif /forums/images/graemlins/peace.gif
     
  18. rjfguitar

    rjfguitar 3/4 ton status GMOTM Winner

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    [ QUOTE ]
    How about doubling the current delivery at all rpms for about $40?



    [/ QUOTE ] I remember your thread about it. /forums/images/graemlins/wink.gif... And considered it myself.
     
  19. Blue85

    Blue85 Troll Premium Member

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    Yes, I noticed a difference. My real problem is idling with A/C cranked, headlights on, radiator fans running, stereo playing, etc. I still get a little droop in voltage under these conditions, but at least now the batteries are not discharging. Hopefully someday, it will work for a winch (feel free to send money /forums/images/graemlins/grin.gif), just by adding a hand throttle to turn the engine faster.

    Everything is wired in parallel. That is, all terminals on alternator 1 are connected to the same places as the terminals on alternator 2. You can also disable one or the other for troubleshooting just by pulling the little 2-wire plug out of the side. There is no guarantee of load sharing and in fact, alternator 1 provides most of the current until the load gets big. I beefed up the alternator to starter wiring while I was doing this.
     
  20. 88K5Jimmy

    88K5Jimmy 1/2 ton status

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    I too have some of the same power draws, headlights, a/c blowing, stereo and when I use the power windows in conjunction with all of that. Maybe putting the extra alternator in there could just help out with those functions.

    Also, what belt did you use or did you just measure and find one at the parts store?

    Thanks
    Ross
     

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