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Plow light problem

Discussion in 'Blizzard Plows Discussion' started by bpoint, Nov 4, 2011.

  1. bpoint

    bpoint Junior Member
    Messages: 6

    I have a Blizzard 800 on a 2008 GMC 2500 and upon hooking up the lights this season noticed that they didn't work correctly when switching from truck lights to plow lights.

    I think the problem is with a driver's side relay.

    When everything is connected the driver's side headlight is on, and the passenger's side plow light is on. Toggling the switch in the cab between plow and truck lights does nothing. Both the turnsignal and headlight on the driver's side do not work.

    If I disconnect the driver's side plow light (re-connecting to the "off-season" plug) the switch then works, toggling between the truck lights and the still connected passenger side plow light. I checked the bulbs on the driver's side, they do work. When the plow lights are not connected, the truck lights switch between high and low beam without any issues. Am I right that it is likely a relay?
    I am unsure how to go about identifying and changing out the relay, but before I try to figure that out, I thought I would ask if that sounded like the problem.
    Last edited: Nov 4, 2011
  2. Sharpcut 1

    Sharpcut 1 Senior Member
    Messages: 385

    A 2008 GMC will have an extra relay that is powered up by the battery. Follow the red and black skinny wires from the battery to a little black module. Test if you have power going in and out of the module. There is an inline fuse in the red line. IIRC, it is triggered by the brown running light wire. 2008 GMC will have high and low beams on at the same time (on the truck) this is too much draw with the plow. That is what the extra module is for. There should also be a grey and purple wire coming out. Make sure all 4 wires are still connected. Sounds like the fuse blew or you lost running light power, since running light is not also working on your plow.
  3. bpoint

    bpoint Junior Member
    Messages: 6

    I just ran out to check the fuse on the red line. It is intact, and when I disconnect, it turns the light off on the passenger side plow light. I will spend more time looking at the lines in the daylight tomorrow. I changed the battery in the spring. Maybe I jostled something loose.

    Thanks for the reply!
  4. beam

    beam Senior Member
    from pa
    Messages: 314

    check grey wires for park lights
  5. bpoint

    bpoint Junior Member
    Messages: 6

    On the driver's side there is a red line coming off of the engine compartment fuse box. That line also has an inline fuse. That was where my problem was. It looks like one of the nibs on the top of the holder broke allowing it to separate completely and the fuse fell out. I replaced the holder and put in a new 14A fuse. Works now. Should've noticed it earlier, but didn't really know what I was looking for. Thanks for the help!

  6. Sharpcut 1

    Sharpcut 1 Senior Member
    Messages: 385

    Each side has it's own module. Follow the red wire and you'll find the module it powers up.