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'71 CJ5 Alternator w/ built in volt reg

Discussion in 'Early CJ5 and CJ6 Tech' started by Hazzo, Sep 17, 2009.

  1. Sep 17, 2009
    Hazzo

    Hazzo New Member

    Piqua, OH
    Joined:
    Jun 22, 2009
    Messages:
    5
    I cannot find a replacement OEM voltage regulator, with three wire plug in that attaches to passenger side fender well under hood. I was told to get a 63 amp GM alternator with a built in voltage regulator from the local auto parts store. Any suggestions what year/make vehicle to reference when asking? I have a 225 Dauntless V6. Thanks.
     
  2. Sep 17, 2009
    EricM

    EricM Active Member

    Southern California
    Joined:
    Dec 19, 2007
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    1,019
    There's a pretty good description here:

    http://www.madelectrical.com/electricaltech/delcoremy.shtml


    For my F134, I got:

    10SI, 63 amp, at 3:00 (AC-DELCO # 321-39, Lester #7127-3)
    Tell the auto parts counter person that “The alternator is for a 1978, Chevy Camaro, 8cylinder 350engine, with air conditioning.”

    There are more suggestions in the above link.
     
  3. Sep 17, 2009
    timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

    Medford Mass USA
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    Rockauto.com shows your part in Delco:
    [​IMG]

    C628 Delco. Airtex 1V1177 too. Any auto parts store should be able to get this part.

    The Delco alternator is a good upgrade, but you don't have to upgrade.

    The Motorola alternator pops diodes pretty often. Make sure it's regulator at fault and not a diode in the alternator.
     
    Last edited: Sep 17, 2009
  4. Sep 17, 2009
    davistroy

    davistroy Grasshopper

    Marietta, GA
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    Jul 30, 2009
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    432
    I just went through this. I think I got a 1984 Camaro Hi performance (305 cu. in. 4bbl Model "G"), which I think is a 12SI. From all of my research this seems to be the best and easiest GM 3 wire alternator for older CJ's:

    Oreilly has them (but any FLAPS should carry them):

    Ultima - Alternator
    Part Number: 01-0266
    Remanufactured
    94 Amps
    Caution: Pulley Change May Be Required
    Limited Lifetime Warranty

    I learned a lot from here:

    http://www.madelectrical.com/electricaltech/remotevoltagesensing.shtml
    http://www.madelectrical.com/electricaltech/onewire-threewire.shtml
    http://www.madelectrical.com/electricaltech/delcoremy.shtml
     
    Last edited: Sep 17, 2009
  5. Sep 17, 2009
    cj6/442

    cj6/442 Sponsor

    Fallbrook, Calif
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    timgr,is there a way to check the voltage reg, I have a new batteryand new rebuilt alt . or should I just pick up a reg at this point.
     
  6. Sep 18, 2009
    timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

    Medford Mass USA
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    Here's a VR-alternator circuit:

    [​IMG]

    It's from this site: http://www.familycar.com/Classroom/charging.htm

    Basically the VR controls the voltage to the alternator field coils. If the battery drops below a set voltage, the VR sends voltage to the field coils and energizes the alternator. If the VR is defective, then the alternator will just spin and create no voltage, or could send voltage to the field coils constantly (much less likely). So, 1) check the field voltage output from the VR.

    The other most likely problem is bad rectifier diodes, or bad diode trio. The exact arrangement of the diodes is specific to the alternator, and will be shown in the FSM. When the rectifier diodes fail (go open), the output of the alternator decreases. This basically chops the output (the output is rectified AC), so the alternator can check out ok on a tester and not charge effectively. Then 2) check the alternator output compared to the field voltage. If that checks ok, then 3) I'd open up the alternator and check continuity of the diodes with my multimeter.

    A bad diode trio could cause VR to detect the wrong voltage, affecting the VR operation. In the diagram, a bad element in the diode trio could lower the sense voltage to the VR, causing an overcharging condition.

    Please check the FSM and compare its diagrams to these. There will be differences, but the basic function will be the same.
     
    Last edited: Sep 18, 2009
  7. Sep 18, 2009
    Walt Couch

    Walt Couch sidehill Cordele, Ga. 2024 Sponsor 2023 Sponsor 2022 Sponsor

    cordele, Ga.
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    So what are we working on here? The thread started by Hazzo is in ref to Motorola system and then jumps to Delco and then back to Motorola ext reg and I am not sure if anybody has gotten their answer. Should we start this one over or can the originator tell us if he has his problem solved?
     
  8. Sep 18, 2009
    Mcruff

    Mcruff Earlycj5 Machinist

    Albertville, AL
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    Sep 22, 2002
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    Just for the sake of info. You do not need a specific application for the Delco alternator. Just a generic GM alternator will work with the internal regulator. If the clocking on the plug becomes a problem simply undo the 4 bolts and rotate the housing till the plug is where you want it. All you really need to make sure of is that the pulley is the right type, v-belt versus serpentine. The Delco internal regulated alternator will clean up your engine compartment and wiring a little and is easier in the end to deal with. It will also bolt right in place of the factory Motorola if that is what you have stock. Me I wouldn't waste my money on a regulator unless you want the system to stay stock. The Motorola and stcok Delco on these old jeeps is so low on output (30-35 amp) that its pitiful. Go with a Delco internally regulated 64-94 amp alterenator and forget about it.
     
  9. Sep 18, 2009
    Patrick

    Patrick Super Moderator Staff Member

    Los Alamos, NM
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    He asked about finding a regulator for his original Motorola,and also about converting to a I.R. Delco. Both questions recieved answers.
     
  10. Sep 18, 2009
    timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

    Medford Mass USA
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    Another comment - if you have an original ammeter, it's meant to work with the range of output of the original alternator. Add a 60A or 90A alternator and all the charging current is still going through the shunt in your ammeter - not good. Much heat will be generated, and there could be a fire.

    If you are in this position, I'd suggest you replace the original ammeter with a voltmeter, and bypass the under-dash wiring for the charging circuit altogether. MadElectrical http://www.madelectrical.com/electricaltech/amp-gauges.shtml has a pretty good article about this.

    The ammeter in my pickup is bypassed, even though I'm running the original wimpy alternator.
     
  11. Sep 18, 2009
    Patrick

    Patrick Super Moderator Staff Member

    Los Alamos, NM
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    That's why I run a volt meter. I really didn't want to run my main power (charge) wire into the cab. For an ammeter to be accurate, everything electrical except for the starter motor needs to run thru it...
    I've found the volt meter tells me enough about the status of my charging system.
     
  12. Sep 18, 2009
    Mcruff

    Mcruff Earlycj5 Machinist

    Albertville, AL
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    I also run a volt meter with my 64 amp alternator.
     
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