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roof beacon light

Discussion in 'Chevy Trucks' started by BOBKAT, Jan 25, 2003.


    BOBKAT Junior Member
    from NH
    Messages: 5

    I am new to the forum.
    I could use some help in powering up a flashing light on the roof.
    My truck is a 2003 Chevy and the wiring and fuses are different than the 2002s. I have the plow package which provides wiring over the headliner and a switch in the dash for the plow light. On the 2002 Chevys all I had to do is connect the wires over the headliner to the light and turn the switch on, all wires, fuses and relays came from the GM ready for use. On my 2003 The switch lights up when on, but I am not getting power to the roof wiring. The fuses and relays don't match what is shown on the GMUPFITTERS site. Are there any schematics available for the 2003s? or has anyone figured this new wiring out yet?

    I appreciate any help
  2. Dan S.

    Dan S. Member
    Messages: 31

    I am no expert on plow set-ups but from your description it sounds like the circuts have been seperated on your 03 model. You may need an additional switch to control the relay for the over head power or you might be able to control multiple relays with one switch. If all else fails trace out the circuts, maybe something was not connected properly at the factory.
    Good Luck:)
  3. Pelican

    Pelican 2000 Club Member
    Messages: 2,075

    Have you looked in your glove box or console yet? Ford stows the fuses for the towing package in the glove box, auxillary power to the trailer won't work until it's installed. Maybe Chevy is doing something similar.
  4. sonjaab

    sonjaab PlowSite.com Addict
    Messages: 1,425

    BOB... YOU do have the factory VYU plow prep. pkg.
    right? You do have the aux. light switch next to
    the pass. air bag cut off switch ? Are ya sure ya
    got the right wires ? One heavy brown + and one
    heavy black - both deadheaded above the
    roof liner? Is there power to them with a test light ?
    Beacon Shot ? They run up the rear drivers side pillar
    that is where the relay is (at least 99-02) maybe relay
    is bad.....Most Chevy dealers are clueless... Thats why
    Plowsite and a few others are the places to ask ! Try
    Last edited: Jan 26, 2003

    BOBKAT Junior Member
    from NH
    Messages: 5

    Yes I do have the plow prep package , it has a switch in the dash next to the air bag switch. This switch is for a roof beacon light. The only two wires I found over the headliner was a brown and a gray. They had the ends taped. When I turn the plow light switch on I hear a thump in the drivers side speaker but it does not sound like a relay. The gray wire is ground. I have checked for voltage with the dash switch on(its indicator light is lit), there is no voltage. I have checked between each wire to ground and between the two wires, even checked for reversed polarity. I have checked for power with the headlights and cargo light on incase ther were other wires, still no power.

    Thanks for the help
    we might find the problem yet without striping the truck

  6. wxmn6

    wxmn6 PlowSite.com Addict
    Messages: 1,037


    Since your truck is new, your truck is still under warranty. Bring it to your dealer and let them fix the problem so no headache for you.
  7. wxmn6

    wxmn6 PlowSite.com Addict
    Messages: 1,037

    Maybe you can check and see if the fuse is blown, or loose, or missing?

    As for thump sound, alot of people reported the same thing. I would assume that it is nornal but I cannot confirm that.
  8. sonjaab

    sonjaab PlowSite.com Addict
    Messages: 1,425

    BOB...On the drivers side rear pillar (near upper seat belt
    anchor is where the relay is located. Maybe its bad or a
    wire is disconnected. GM upfitter and my o1 say and have
    2-12 guage wires......onebrown+ and one black -.
    There was a couple of other wires up there powering the
    roof lamps too.......It is a PIA to get to it because you have
    to remove the rear seat to take off the piece of corner
    plastic and upper belt bolt. (on a x-cab). I just took the
    roof door striker off..pulled the headliner down gently and
    fished out the 2 wires and put female ends on them and
    male ends on my magnetic beacon.
    Print out the upfitter link and take it to GM dealer cuz your
    under warranty. You know they prob. are clueless !!!!

    You should also have a 30 amp marked SEO 2 fuse in the underhood power center. Check and see if its blown out !
    This powers the aux. light switch , relay and beacon.......
    It should be just above your radio fuse in the underhood
    elec. ctr.....I will check mine and repost ! Snowing good out
    not gotta go play and will check my rig.....THEN BOWL TIME !
  9. SnowMatt13

    SnowMatt13 PlowSite.com Addict
    Messages: 1,559

    Bob... I found out about this option on my 2001 2500HD. Put my light on my backrack with 6 feet of wiring wound up, took it to my Chevy dlr. and for $25 they made it work. Can't beat that, because if something happens and it stops working it gets fixed for free:p