1. Thank you for visiting HeavyEquipmentForums.com! Our objective is to provide industry professionals a place to gather to exchange questions, answers and ideas. We welcome you to register using the "Register" icon at the top of the page. We'd appreciate any help you can offer in spreading the word of our new site. The more members that join, the bigger resource for all to enjoy. Thank you!
  2. ALL NEW MEMBERS READ THIS FIRST!! Thank you for joining Heavy Equipment Forums! If you are new to forums we communicate with "Threads", please search our threads to see if your topic may have already been answered and if not then click "Post New Thread" in the appropriate forum. This will allow all of our members to see your question and give you the best chance to be answered. After you've made a number of posts you will graduate to Full Member status where you'll see a few more privileges. Following these guidelines will help make this the best resource for heavy equipment on the net. Thanks for joining us and I hope you enjoy your stay!!

D4C Series III Electrical Schematic

Discussion in 'Dozers' started by d9gdon, Aug 12, 2018.

  1. d9gdon

    d9gdon Senior Member

    Joined:
    Feb 12, 2010
    Messages:
    1,496
    Location:
    central texas
    Would someone please post an electrical schematic for a D4C Series III SN 6YL2167? I have no power at the hour meter. I've had trouble with corroded wiring connectors on the alternator side, so I have a feeling that is also my trouble here. I need to rewire my backup alarm and lights as well.
     
  2. kshansen

    kshansen Senior Member

    Joined:
    Mar 11, 2012
    Messages:
    10,500
    Occupation:
    Retired Mechanic in Stone Quarry
    Location:
    Central New York, USA
    Here's what I see on SIS:
     

    Attached Files:

  3. d9gdon

    d9gdon Senior Member

    Joined:
    Feb 12, 2010
    Messages:
    1,496
    Location:
    central texas
    Thank you for that information.

    I see the problem already...same plug where the alternator wire was corroded.
     
    Last edited: Aug 12, 2018
  4. d9gdon

    d9gdon Senior Member

    Joined:
    Feb 12, 2010
    Messages:
    1,496
    Location:
    central texas
    Nope that wasn't it.

    I have no power coming from the alternator on the green 403 wire that goes to the hour meter. I did unplug the harness from the alternator and jumped power to the green wire and the hour meter does work, but if I plug it into the alternator I get no power on the green wire.

    I have battery power on the purple wire there and then I get voltage on the yellow wire when I crank it but none on the green wire. The yellow wire goes to the charging light which was burnt out but I replaced it and it works now.

    I just replaced that alternator with a Cat reman last Saturday. Hour meter wasn't working before that either.

    There's a connector that the yellow wire runs through...I have power on both sides of it with a digital volt meter, but not with a test light. However, I think that's because I'm providing a ground to the lamp when I use the test light which energizes the lamp circuit. I think that yellow wire is a neutral from the alternator except when running which energizes it and makes the lamp go out. So I don't think a test light will tell me anything since it acts both ways.

    I have checked output on the green wire with the engine running with both the DVM and the test light and get nothing.
     
    Last edited: Aug 13, 2018
  5. Cmark

    Cmark Senior Member

    Joined:
    Jan 2, 2009
    Messages:
    2,983
    Location:
    Australia
    Is it charging OK? What voltage are you getting at the B+ terminal when running? You may need to excite the alternator.
     
  6. d9gdon

    d9gdon Senior Member

    Joined:
    Feb 12, 2010
    Messages:
    1,496
    Location:
    central texas
    I'm getting 13.8-14.5v at the alternator wire and at the battery.
     
  7. jwest75801

    jwest75801 Well-Known Member

    Joined:
    Feb 8, 2012
    Messages:
    122
    Occupation:
    Owner operator
    Location:
    texas
    You probably have a broken prong on one of harness connectors I have had this problem several times.