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10si or 12si alternator on dauntless

Discussion in 'Early CJ5 and CJ6 Tech' started by homersdog, May 6, 2012.

  1. homersdog

    homersdog Tulsa, Ok 2024 Sponsor 2023 Sponsor 2022 Sponsor

    Fellows,
    I am planning to upgrade my alternator on the 71 dauntless from the original motorola 35 amp to a delco 10si or 12si. I have been reading as many threads as I can find on the subject, but I can't find one that answers questions on the physical size. I found dimensions for the the 10si & 12si on a chevelle website, and the front to back length is shown to be either 6.5" or 6.63". A tape measure check on the jeep shows 6.5" will put the back of the new alternator right against the valve cover.

    Does anybody have any pics of their installed 10si or 12si (on a dauntless) that they can share? Or if you can just ease my worries by telling me it bolted right up, I would appreciate it. The wiring up of the new alternator is not a problem for me, I just want to make sure it will fit.

    Thanks
    [​IMG]
     
  2. supertrooper

    supertrooper Member

    [​IMG]
    it looks close but doesnt hit anything and the pully lines up perfectly.
     
  3. ojgrsoi

    ojgrsoi Retired 2024 Sponsor 2023 Sponsor 2022 Sponsor

    It fits using the factory bracket. The first photo is the best side shot I have and the second shows a better shot of the bracket. The pigtail with the red and white wires is available at the parts store.
    Don't overtighten the pivot bolt. And don't ask me how I know.:oops:
    [​IMG]

    [​IMG]
     
  4. homersdog

    homersdog Tulsa, Ok 2024 Sponsor 2023 Sponsor 2022 Sponsor

    Thanks guys, Those photos are perfect!

    Supertrooper your sure have a pretty engine!

    I am headed to the pull a part tomorrow for my new amp supply.
     
  5. Patrick

    Patrick Super Moderator Staff Member

    [​IMG]
     
    OrangeCJ5 likes this.
  6. homersdog

    homersdog Tulsa, Ok 2024 Sponsor 2023 Sponsor 2022 Sponsor

    Thanks Patrick, thats a sharp looking Dauntless!
     
  7. army grunt

    army grunt Member

    What a great looking engin compartment Patrick.I like the clean look of everything. Army
     
  8. Nightstr

    Nightstr Member

    I see some of you aren't running the pigtails. Do you really need them?
     
  9. homersdog

    homersdog Tulsa, Ok 2024 Sponsor 2023 Sponsor 2022 Sponsor

    madelectric.com seems to be an authority on these, and he recommends the three wire over the one wire setup because it provides remote sensing and therefore more accurate voltage control where you need it.
     
  10. nickmil

    nickmil In mothballs.

    No but they are cheap, don't come unplugged on their own, and make for a clean setup.


    Sent from my iPhone using Tapatalk
     
    Mike C likes this.
  11. duffer

    duffer Rodent Power

    Patrick's appears to be a one wire alternator-which you will have to be very lucky to find at the pick and pull. They can be had at most parts houses for $80 to 90 for a 100A version and do make a clean, easy install. I still like the 3 wire for reasons stated above but the one wire versions work well, especially on things like old tractors running a mag. On a one wire, you have to kick up the rpms for them to self excite but that is a minor issue.
     
  12. EricM

    EricM Active Member

    A CS144 will also fit, but it's a bit of overkill.
    A 120 amp alternator for $30 at our local pick a part, $15 on half price day.
    I pick one up, then take it to the local autozone/o'reillys and have them test it.
    You'll find them on early to mid-90s cadillacs and some buicks.
     
    Last edited: May 11, 2012
  13. homersdog

    homersdog Tulsa, Ok 2024 Sponsor 2023 Sponsor 2022 Sponsor

    Bought a rebuilt 10si from a guy on ebay, he rebuilds them for hot rodders. It is set up for 100 amp. Cost was $80, free shipping. Installed it this morning, three-wire. Runs like a champ.

    The old wiring scheme from the motorola alternator ran the main wire up to the stewart warner amp meter in the instrument panel. This wouldn't work with a 100 amp alternator. I used 6 gage wire and ran the main cable and the remote sensing cable straight down to the distribution post on the starter. Soldered all wire terminals with rosin core high temp solder. Ran the #1 terminal to the orginal charge light in the speedo cluster and it works great. I am going to put in a voltmeter in the hole where the amp meter was.

    As far as remote sensing goes, my experience in a similar application was as the manufacturing engineer for a trolling motor company. we built all our own 12,24 and 36 volt PM dc motors and 100% dyno tested using a PC controlled dyno with a analog and digital I/O card setup on the PC. The card was only a few feet away from the test units. The only way I could keep accurate voltage at the motors during high amp draw (25-75 amps) was to have the voltage sensing as close to the brushes as possible.

    THANKS EVERYONE FOR YOUR HELP AND PHOTOS!
     
  14. Rick Whitson

    Rick Whitson Detroit Area 2024 Sponsor 2022 Sponsor

    I bought one off E bay 110 amp, chromed, for $68.00, free shipping, but don't recommend it. Rebuilt in China, it works OK but I kike American.
    Beautiful motor Patrick, nice, nice, motor.
     
  15. Twin2

    Twin2 not him 2024 Sponsor 2023 Sponsor 2022 Sponsor

    do you really need more than a 63 amp
     
  16. colojeepguy

    colojeepguy Colorado Springs

    I put a 100A unit on mine, because of the electric winch.
     
  17. CJ Joe

    CJ Joe Truckhaven Tough!

    Same here. I have a 120 amp CS144 because of the electric winch. Unless you have some sort of high ampere equipment there would be no need for it.
     
  18. nickmil

    nickmil In mothballs.

    If you plan on running high amp draw items like a winch or jump start other vehicles it sure is nice to have higher amp output. Never heard of a problem with a high amp alternator being a problem when the max output is not needed.
    Going from memory but it's not recommended to utilize more than 85% of max rated output for any length of time. Reason being heat and longevity.
     
  19. Rick Whitson

    Rick Whitson Detroit Area 2024 Sponsor 2022 Sponsor

    I have an 4000 watt inverter just in case I need one.
     
  20. CJ Joe

    CJ Joe Truckhaven Tough!

    4000 or 400? At 4000 watts you'd need a whole bank of batteries.