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2003 2500hd roof light no power

Discussion in 'Chevy Trucks' started by jtmonte, Jan 28, 2013.

  1. jtmonte

    jtmonte Junior Member
    from ny
    Messages: 20

    snaked out the accessory roof light wire, hooked it up to test light and no power (with switch on obviously).

    located the relay behind the driver side pillar, how do i test/know if the relay is good? with the relay disconnected, i tried putting a test light to each wire (i think there were 4) and no power from any of those either.

    what else should i look at?
     
  2. Landscapes8988

    Landscapes8988 Senior Member
    Messages: 106

    can't help you but was wondering where the wire was on your truck. pulled my headliner down a little on the driverside today but didn't see anything.

    also i read somewhere there is a 30amp fuse for it somewhere (i think the fuse block under the hood but i am not 100%)
     
  3. jtmonte

    jtmonte Junior Member
    from ny
    Messages: 20



    make sure you have the plow package (should have a switch to the right of the radio)

    i pulled off the pillar where my rear driver side speaker is and then pryed down the head liner on my driver side, the wires were bundled up about a foot or so in, there should be 2 (1 brown 1 black ) tied together
     
  4. Landscapes8988

    Landscapes8988 Senior Member
    Messages: 106

    yea i have the plow package... i pulled the pillar up front. I will check the rear pillar tomorrow. thanks
     
  5. mike1316

    mike1316 Senior Member
    Messages: 155

    Make sure there a fuse in the spot mine did not have one in it.
     
  6. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    The 12v feed for the relay is the orange wire. And it receives it's power from the "SEO B2" fuse in the underhood fuse panel.

    The roof beacon harness option is tied in at the Mid Buss panel under the dash, be sure it's plug is fully seated in the panel,
     
  7. jtmonte

    jtmonte Junior Member
    from ny
    Messages: 20

    I am at wits end ha, changed relay so that's out.

    I have power at the relay only with the white wire. I have power under the dash at the small orange wire (which I'm assuming is the orange wire at the switch that gets connected to the white sending power to relay)

    There is no power coming out of the relay.

    What is the large orange wire?
     
  8. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    The white is the trigger wire from the switch, that tells you the SEO B2 fuse is good as it feeds the switch. So you're good there.

    Check the SEO B1 fuse next. It feeds the large orange batt+ at the relay. Use a testlamp on both sides of the fuse to check it. Don't simply rely on a visual inspection.

    If it's ok make sure the "Stud 2" fuse is in place and not blown It supply's power to both the SEO B1 and B2 fuses among other things.
     
  9. jtmonte

    jtmonte Junior Member
    from ny
    Messages: 20

    i traced the large orange wire out where it hooks up to the mbec and moved it to a different slot (one fused by seob1, which was a 15 amp fuse). i replaced the 15 amp fuse with a 20.

    all seems well so far.


    i checked the stud 2 fuse everything is fine there, i do remember reading somewhere that the early GMs in 2003 had a wire missing or something to that effect i am wondering if i am victim of this as i am not getting power to the prong on the mbec that powers the accessory roof light.
     
  10. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    The "missing" wire wasn't to power the stud because the stud is already constant hot directly from the battery. What you're thinking of is the trailer feed wire. That had to be added to the stud manually. So none of that would apply to why your feed to the roof relay was dead.

    If you're now using a circuit fed by the SEO 1 fuse, then Stud 2 has to be fine, because both the SEO 1 and SEO 2 fuses are powered by Stud 2 and it's fuse. So the problem is somewhere between the SEO 2 fuse in the underhood panel and the MID Buss panel under the dash. Just an FYI.