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74 alternator

Discussion in 'Intermediate CJ-5/6/7/8' started by dbender, Apr 20, 2011.

  1. Apr 20, 2011
    dbender

    dbender 1974 CJ5 I6 258

    San Pedro California
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    Oct 19, 2010
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    257
    Help....in over my head.....
    74 cj5 restoration.... painless rewiring kit......Cant remember how alternator connected. or which posts are which... Painless knows a lot about their stuff but not much on where to connect it.... I have the battery feed and an exciter wire from the harness. the regulator has four wires coming off it..I have the original wiring diagram from the manual.. and cant figure this thing out... any suggestions!!!!!!!!!
    Dave
    how do you get photos from photo bucket to here? Been trying for 45min or okay hours

    I believe the alternator is a motorola. the wires from the regulator are yellow. green black and orange. Green & black go from the regulator to the 90degree posts on the alternator. the yellow I believe connects to the excitor wire off the harness. The one i am not sure of is the grey off the old harness. It attached some where on the alternator then went elsewhere, maybe to the ignition switch, don't know. I am still tryin to get the pics up
     
    Last edited: Apr 21, 2011
  2. Apr 21, 2011
    timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

    Medford Mass USA
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  3. Apr 21, 2011
    54cj3b

    54cj3b Member

    evergreen colorado
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    Think this is what he is looking for


    [​IMG]
     
  4. Apr 21, 2011
    Walt Couch

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

    cordele, Ga.
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    The grey from the regulator goes onto the small (longer) stud that goes thru the diode plate (should be red plate) and the second grey wire connects to the same terminal and goes to the alt/gen light which then goes to the ign switch.
     
  5. Apr 21, 2011
    dbender

    dbender 1974 CJ5 I6 258

    San Pedro California
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    Ok this is the third time I have tried to reply to this post and I keep loosing it. So here we go again.
    The wiring diagram that I have is the same one TMGR linked to me. Here is what I think has to happen. The yellow off the regulator connects to the Painless #714 (white) excitor wire. The Painless #715 (red) connects to the battery out put post which I believe is the center lower post. The green and black off the regulator connect to the 90 degree tabs at the top of the Alternator respectively. The orange off the regulator connects to the grey (original harness) (c-6) which painless does not provide in their harness so I will have to run my own.
    Walt,,, there are three posts on the back of the alternator, all are the same diameter, two are the same length and one is a bit longer as you said. The two shorter ones are insulated from the alternator housing and the longer one grounds out on the housing. Which one is the battery out put and do i still connect c-6 to the grounded post or the insulated post.
    Also, what does the Alt light on the cluster signal,, Charging or not charging.
    And is the lead to the ignition from there necessary.
    Thanks for the help guys
    Dave.
     
  6. Apr 22, 2011
    brianmurphy

    brianmurphy 866

    Whitmell, Va.
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    Jan 4, 2007
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    This is from my core. It is a 304 from a '74. hope it helps.


    [​IMG]
     
  7. Apr 23, 2011
    dbender

    dbender 1974 CJ5 I6 258

    San Pedro California
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    Oct 19, 2010
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    Yes it does help. thank you very much. My Alternator is the same only on the straight 6 it is on the passenger side and rotated 180 degrees from your picture.I wired it exactly like yours is. But what about that grey wire to the Instrument cluster alt light ??????? A must or not ????????

    Dave
     
  8. Apr 24, 2011
    Walt Couch

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

    cordele, Ga.
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    The power thru the ALT indicator light is used to trigger the alternator rotor residual magnetism so the unit will begin producing output at low RPM. Sometimes the alt will begin charging when revved up and sometimes it won't. If the rotor has lost all residual mag from long time storage or rough handling, it sometimes will not charge at all until an initial shock voltage is applied at the grey wire terminal.
     
  9. Apr 24, 2011
    dbender

    dbender 1974 CJ5 I6 258

    San Pedro California
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    RGR Got it.... so the grey wire connection to the ignition or (power source) is only to light the light which then sends a lower voltage to the regulator ?????? do I have this correct ?????

    Dave
     
  10. Apr 24, 2011
    Walt Couch

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

    cordele, Ga.
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    It actually sends an exciter voltage (12.5V) to the diode trio (inside alt) and to the regulator then when the alt begins to produce power, the voltage on the grey wire will be about 2 volts above battery voltage which is not enough to light the alt light. That is how you know it is charging.
     
  11. Apr 25, 2011
    dbender

    dbender 1974 CJ5 I6 258

    San Pedro California
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    Oct 19, 2010
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    OK Roger That, Thank you so much for the lesson. This stuff is fascinating. I will follow the wiring diagram and run the grey wire from the Alternator to the alternator light in the instrument cluster and then to the ignition as shown.
    Thank you again for your help walt.

    Dave
     
  12. May 16, 2011
    dbender

    dbender 1974 CJ5 I6 258

    San Pedro California
    Joined:
    Oct 19, 2010
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    IMG_3377.jpg


    I wired the alternator as per the jeep diagram. the alternator light on the cluster stays on when the ignition is off and goes out when the ignition is on..... if I disconnect the wire from the left post. Which is hot when the ignition is off ???????? then the light goes out on the cluster and comes on when the ignition is turned on....... oh what to do

    Not so Painless
    Dave
     
  13. May 16, 2011
    dbender

    dbender 1974 CJ5 I6 258

    San Pedro California
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    Oct 19, 2010
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    And I can not seem to get these dam photos off bucket to the thread???????????
    Having a tuff go here

    Dave
     
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