Service Trailer Brake System activates only when plowing

Discussion in 'Chevy Trucks' started by Motorman 007, Dec 4, 2019.

  1. 2015 GMC 2500 HD Fisher XV plow. Service trailer brake system light and alarm activate from time to time plowing. One would assume this is a wet wiring or plug issue but it never does it in the off season even when driving in heavy rain and puddles. Any ideas?
     
  2. cwren2472

    cwren2472 PlowSite Fanatic
    Messages: 7,118

    Snow build up getting kicked into the back of the plug and sticking there
     
  3. OP
    OP
    Motorman 007

    Motorman 007 Senior Member
    Messages: 917

    Have you seen this before??
     
  4. cwren2472

    cwren2472 PlowSite Fanatic
    Messages: 7,118

    Yes. It happens on aftermarket controllers also and often shows as flickering displays. I wouldn't say it's common but it happens. The back of the factory plugs are pretty poorly sealed.
     
  5. Mark Oomkes

    Mark Oomkes PlowSite Fanatic
    Messages: 29,226

    Toro supplies them to GM?
     
    m_ice likes this.
  6. cwren2472

    cwren2472 PlowSite Fanatic
    Messages: 7,118

    Actually it's one of the few universal pieces in the auto industry. Its called USCAR and despite the US in there, it's the same socket used by Ford, Dodge, GM, Nissan, Toyota, VW, oh and everyone else too. K, lesson over.
     
    Motorman 007 likes this.
  7. m_ice

    m_ice PlowSite.com Addict
    Messages: 1,799

    There is also a trailer brake controller relay that could be the culprit
     
    Motorman 007 likes this.
  8. OP
    OP
    Motorman 007

    Motorman 007 Senior Member
    Messages: 917

    I pulled everything apart this morning. Absolutely no indication of moisture penetration from the back side of the plug. Cleaned it up anyway and put some dielectric grease on the plug terminals inside the bumper socket. We’ll see but I’m not encouraged.