1. Welcome to PlowSite. Notice a fresh look and new features? It’s now easier to share photos and videos, find popular topics fast, and enjoy expanded user profiles. If you have any questions, click HELP at the top or bottom of any page, or send an email to help@plowsite.com. We welcome your feedback.

    Dismiss Notice

8600HD no power

Discussion in 'Blizzard Plows Discussion' started by WHITERAM, Nov 25, 2014.

  1. WHITERAM

    WHITERAM Member
    Messages: 32

    help! Have had 8600hd for 3 seasons. Been awesome pusher on my 2012 gmc duramax...until today. Went to pull it out . No power at all. No lights, no hydraulic, no controller. Checked 10 amp fuses. Both are good. Chased wires best I could with flashlight. Wiring looks solid. 14.8 volts out of plow connector. (2 prong) . Not sure how installer ran power and ground. I don't see power Leeds directly to battery.(either one). Any suggestions fellas?
     
  2. bliz&hinikerDLR

    bliz&hinikerDLR Senior Member
    Messages: 471

    Sounds like the iso module is not powering up. Find where the 4-pin vehicle harness connects to a power and ground source. Then trace the two small wires (power and ground) running parallel with the big power wires to the 4-pin quick connect and confirm that plug is plugged into the 4-pin quick connect labeled "BAT". It is possible to get that connection plugged into the wrong plug. Look for damage to the wires.
    Also remember that both plugs need to be plugged into the plow and that the controller needs power from a keyed accessory.
     
  3. WHITERAM

    WHITERAM Member
    Messages: 32

    Ill start chasing wires today. I know the harness is vehicle specific. problem is the OE wiring is 10 pounds of Bologna in a 2 pound sack. No room o work or look. half tempted to pull it all out and start over again. Had a glow plug replaced under warranty last month. Wondering if the technician unplugged something while replacing.
     
  4. dieselss

    dieselss PlowSite Fanatic
    Messages: 10,963

    I'd start at the batts, he may have forgot to hook up a wire or something
     
  5. WHITERAM

    WHITERAM Member
    Messages: 32

    At the 4 prong BATT connector...ive got power 2 legs of the 3 wires. plow is unhooked at this point. should 3rd leg go hot when connected ? or hot all the time.?

    anyone have a pin out diagram of isolation module?

    what a mess...
     
  6. dieselss

    dieselss PlowSite Fanatic
    Messages: 10,963

    Blizzards website will
     
  7. WHITERAM

    WHITERAM Member
    Messages: 32

    tried there. module is 29070-1. no schematics :(
     
  8. WHITERAM

    WHITERAM Member
    Messages: 32

    Whats the chance Iso module is bad? everything seems to be hot and round where needed. nothing has changed. just no power...anywhere....
     
  9. WHITERAM

    WHITERAM Member
    Messages: 32

    update: swapped isolation module...still same issues. common ground or common voltage problem...
     
  10. dieselss

    dieselss PlowSite Fanatic
    Messages: 10,963

    I'll try and look better at home on laptop, phone wasn't that good today
     
  11. WHITERAM

    WHITERAM Member
    Messages: 32

    Ty. Solenoids on pump clock when I connect but still no lights. No plow control. Mo lights on controller. Getting frustrated
     
  12. bliz&hinikerDLR

    bliz&hinikerDLR Senior Member
    Messages: 471

    I highly suspect this is the cause of your problem.

    That is correct. Only two pins on the on the 4-prong plug should have power until the plow is connected and the iso module powers up the controller. Remember that 11 pin plug must be connected to the plow for your controller to have power. I attached a full diagram of the iso module for you with arrows to indicate where to test for power and ground.

    Solenoid will often click once or continuously when there is low battery voltage or poor ground. It does not necessarily relate to your power problem but will probably require attention.

    Keep your cool. It doesn't help you diagnose a problem if you get in a hurry and skip steps or mis-test. Take a breath. I have given you the information that should help you find the problem and we are here to help if you have questions.
     

    Attached Files:

  13. WHITERAM

    WHITERAM Member
    Messages: 32

    My gut is telling me bad ground somewhere. Is the ground to battery in passenger side only ground in entire system? That ground connects to plow control harness
     
  14. bliz&hinikerDLR

    bliz&hinikerDLR Senior Member
    Messages: 471

    With what you have said so far, it does not appear that you have ground. Likely one of these problems:
    11 Pin Plug of plow is not plugged into the truck
    Single pin connector with black/orange wire near iso module is not properly connected.
    Small ground wire parallel with the big ground wire is damaged or harness is not connected to ground at battery.
    The two 4-pin connectors are switched and not plugged into the right connector.
     
  15. bliz&hinikerDLR

    bliz&hinikerDLR Senior Member
    Messages: 471

    Yes. The only ground for the entire system is the one that connects to the battery with one ring terminal. There is one large wire and one small wire that come off that ring terminal.
     
  16. WHITERAM

    WHITERAM Member
    Messages: 32

    Ok. When testing today, I was in my shop(dealership). Just truck. Plow at home but tested by plugging into brand new plows on new trucks. I didn't see a small ground wire parallel with large ground wire. Only one large ground connection at passenger side battery. The single ground connector with orange and black is snug by ISO. 4 pin connectors are on opposite sides of engine compartment. However....on the 4 prong connector, closest to ISO....if I put a jumper HOT to accessory wire, plow moves??? Make any sense?
     
  17. bliz&hinikerDLR

    bliz&hinikerDLR Senior Member
    Messages: 471

    I should clarify. This is true for the 4-pin connector NOT labeled BAT. The 4-pin connector that comes from the battery should only have power on 1 pin.
     
  18. bliz&hinikerDLR

    bliz&hinikerDLR Senior Member
    Messages: 471

    What do you mean plow moves?
     
  19. WHITERAM

    WHITERAM Member
    Messages: 32

    and it does...only one pin...the opposite side 4 pin connector has power on 2 pins. we are on par there.

    It moves: It powers up joystick and i can operate the plow. weird, eh? but still no lights. in the same 4 pin connector, the accessory wire is one that runs through firewall. i jump it opposite side of that connector. This is the 4 pin closest to ISO

    [​IMG]
     
  20. WHITERAM

    WHITERAM Member
    Messages: 32

    This is the 4 prong closest to ISO

    2014-11-26 20.58.31.jpg