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2011 Sierra / Western Ultramount No Low Beams

Discussion in 'Western Plows Discussion' started by wakind, Jan 24, 2012.

  1. wakind

    wakind Junior Member
    Messages: 2

    I moved my plow from a 2003 Silverado to my 2011 Sierra, and I needed to convert everything from relays to the isolation module set-up. Isolation and plow harness are new, Headlight Harness is second hand.

    I have everything hooked up, but I one problem - no low beams on either the truck or the plow. If I disconnect the plow, I get them back on the truck. I have done some research on the site, and I see where some have had issues with the A/B side of the low beam connector when they installed the harness into the factory headlights. Since mine turn off when the plow is connected, does that eliminate the possibility or is that a good starting point for me as well?

    Another thing I found for my particular truck is that since my low beams stay on when the high beams are on, it uses a relay on the light harness that comes out of port A and connects to the plow lights. Looks like when High beams are on, relay is powered to break connection to Low. When High are off, Low should be connected. My thinking is if the relay was bad, my lows would stay on when the highs are on, and would work when just the lows are on. Thing cost 50 bucks and is sealed, so I can't just change relays. I see they have a newer part number of 28027-2 to replace mine which is 29859, but looks like it would need an updated light harness as well.

    I know I need to get my multimeter out and check some things, but I was hoping someone else may have had this issue that can give me some advice first.

  2. wakind

    wakind Junior Member
    Messages: 2

    I fixed my own problem and just thought I would post it in case someone else has the same issue. I reveresed the plugs from the A side to the B side that connected to the factory Low Beam connectors - problem solved.

    On a side note, anyone that needs to wire a 2007+ sierra, It is a PITA. Not sure if Silverados are the same, but my guess is yes. There is little room behind the headlights to get to the lighting connectors, and the lights do not pull out like they did on the older body style silverados. My 2003 silverado took me about 30 miuntes to set up, this one took hours.
  3. 00247

    00247 Junior Member
    Messages: 7

    A tip on the headlights. I saw in another thread how easy the grill and lights come out. The plastic piece on top of the hood latch area comes off by removing the plastic push pin locks, easy. The grill has a few screws on top and metal clips that need to be squeezed with a needle nose pliers on the bottom, easy. The headlights have a screw on top, on the inner side by the grill, and one hidden on the outside that you need to loosen the fender liner for. You can see it by looking between the headlight and bumper. Just loosen that one. Then the headlight comes right out. Now the whole front is open and you can admire how cheap modern vehicles are built.
  4. mishnick

    mishnick 2000 Club Member
    Messages: 2,353

    This is obviously the four headlight system. Each bulb on the truck gets two wires to each plug, one Pos and on Neg. Since it doesn't matter which way the power goes through the fillament they don't worry about it at the factory. This means there is no garuntee which wire is where on the plug. So, when Western builds the harness for these trucks they us a special "flipable" plugs so you can plug it in either way. Just by coincidence you lucked in and got both the high beams right and both low beams wrong. So you need to pull the two low beam plugs and flip them 180 degrees where the original truck harness plugs into the Western headlight harness. Note, since both low beams on the plow are dead you have to flip both sides on the truck. Too bad about the difficulty accessing the plugs. It sucks that GM went away from the old style headlights with those two L shaped pins.