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Truck and plow lights flashing

Discussion in 'Truck & Equipment Repair' started by DeltaT, Dec 12, 2015.

  1. DeltaT

    DeltaT Junior Member
    Messages: 5

    I am having an issue with the lights on my Ultramount. I did quite a bit of searching, but didn't really see anyone with the same problem. I have a 2002 2500HD. I traded some HVAC work for the ultramount, but had to put all the truck side stuff onto my truck. After I installed a 3 port 3 plug isolation module onto my truck, I realized the plow was only 2 plug. So I bought the conversion harness to adapt it. Today I finally got everything installed and hooked the plow up. The plow control works fine, but when I turn the lights on, the plow lights and truck lights just flash back and fourth. I will also add that the isolation module I bought was a used unit :(

    This is my first plow, so I am new to all of this. I have good electrical knowledge. Is there something stupid I may have done or overlooked. I appreciate any and all help I can get from here.
     
  2. dieselss

    dieselss PlowSite Fanatic
    Messages: 10,965

    sounds like a ground issue.
    where did you hook the ground for the lights? have the wiring diagrams?
     
  3. DeltaT

    DeltaT Junior Member
    Messages: 5

    I have the main ground bolted to the grounding bracket that the Chevy's have. Everything is grounded back to that location right?

    I will say that I can hear a clicking noise coming from the module when the lights are flashing back and fourth. It's not a sporadic flashing, but a constant flashing almost like a blinker.
     
  4. dieselss

    dieselss PlowSite Fanatic
    Messages: 10,965

    the plow light grounds.
    the ultras have differnt lights then your older ultra.

    what grounding bracket?
     
  5. Randall Ave

    Randall Ave PlowSite.com Addict
    Messages: 1,977

    I assume its a gasser, driver's side left front corner of engine there is a bracket that says ground on it. Just did an install on a chevy. I ran the grounds directly to the battery.
     
  6. dieselss

    dieselss PlowSite Fanatic
    Messages: 10,965

    Ok I know which one your talking about. Alt bracket, aluminum.
     
  7. DeltaT

    DeltaT Junior Member
    Messages: 5

    To the right of the motor there is a junction box that houses the positive connections for the alternator and right above that is a metal bracket labeled GND. Seemed pretty convienent since the side terminal batteries are a pain.

    I did a little more research and saw something about the 2002 Chevy having a switched grounding system? Could this be an issue?
     
  8. DeltaT

    DeltaT Junior Member
    Messages: 5

    It's on my Duramax
     
  9. Randall Ave

    Randall Ave PlowSite.com Addict
    Messages: 1,977

    Yup, even if this isn't his problem he should run a ground strap from the battery to that bracket.
    Don't no if my install works, customer never brought me the used plow he bought, and he ain't answering his phone. Probably a money thing.
     
  10. dieselss

    dieselss PlowSite Fanatic
    Messages: 10,965

    I did a little more research and saw something about the 2002 Chevy having a switched grounding system? Could this be an issue?

    The easiest way would be to test light the headlights and verify.
     
  11. DeltaT

    DeltaT Junior Member
    Messages: 5

    Sorry I worded my question badly. If my truck has a switched ground system, is there something I have to do in the wiring to adjust for it?
     
  12. Randall Ave

    Randall Ave PlowSite.com Addict
    Messages: 1,977

    In your directions for the headlamp connections, it said to check for where your grounds were, and to connect per there instructions, on the plow side headlamp adapters, the ground, or common wire jumped from one plug to the other. You should have connected to the corresponding headlamp plugs with the grounds to the grounds on the plow harness plugs.