# Roof beacon wiring



## JAJA (Dec 15, 2013)

03 silverado w/ plow prep pack I'm trying to get the roof accessory light to work. Found the wires above the headliner, check the seo b1 fuse and stud 2 maxi 30 and that is good. Light comes on the dash but no power to the wires what else am I missing


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## timboy (Oct 8, 2008)

Can you hear the relay clicking when you push the button,it is behind the b pillar cover on the driver side?


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## JAJA (Dec 15, 2013)

I will check tonite if it does or doesn't what should I check


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## 1997chevy (Jan 7, 2014)

Possible bad relay.


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## JAJA (Dec 15, 2013)

That would suck that harness has never been used before just was hooking it up last nite. Snowing tonite it will be a couple days before I get a chance to figure it out


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## BRL1 (Sep 13, 2014)

Did you check fuses?


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## chevyzrule810 (Oct 5, 2010)

If the fuse was bad the light on the button wouldn't light up


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## JAJA (Dec 15, 2013)

ok so working on this roof beacon wiring...truck has plow prep package.. press button on dash light comes on..at the relay using a test light I have power on the white wire only when the button is on nothing at the orange wire checked fuses seo b1, seo b2 and stud 2 maxi fuse all good, followed the orange wire back to the wire box on the drivers side floor by brake pedal (mid buss electrical center) and have no power at the pin that the orange wire plugs into what am I missing


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## dieselss (Jan 3, 2008)

Can you get the wiring diagrams? Other then that, your chasing wires


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## Mr.Markus (Jan 7, 2010)

Check for a fuse labelled sunroof in your Underhood fuse box. If I remember right it's for the aux roof light


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## JAJA (Dec 15, 2013)

Searched around a bit and no I can't find any wire diagrams for that...I will check the sun roof fuse tomorrow and let you know thanksussmileyflaghttp://www.plowsite.com/images/smilies/smilie_flagge13.gif


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## JoeG3 (Oct 21, 2014)

JAJA;1904116 said:


> ok so working on this roof beacon wiring...truck has plow prep package.. press button on dash light comes on..at the relay using a test light I have power on the white wire only when the button is on nothing at the orange wire checked fuses seo b1, seo b2 and stud 2 maxi fuse all good, followed the orange wire back to the wire box on the drivers side floor by brake pedal (mid buss electrical center) and have no power at the pin that the orange wire plugs into what am I missing


Not sure if I'm following right but you should have 2 wires that were blunt cut to hook up to your beacon. If you have both wires one should be positive (+12) when the switch is "on" and the other should be ground (-).

Again I'm not sure if its different then my '15 Silverado but when the indicator light comes on there is +12 on that wire. Have you tried the beacon to see if it lights when connected to the two wires? If your checking at the fuse box and the wires are still blunt cut you will only have half the circuit under power until the beacon is wired in.

Try that first, If that doesn't work I might have a few other ideas.


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## timboy (Oct 8, 2008)

I believe you are correct.


Mr.Markus;1904165 said:


> Check for a fuse labelled sunroof in your Underhood fuse box. If I remember right it's for the aux roof light


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## joshg (Nov 12, 2009)

check out the gmupfitter website. They have lots of good info straight from the source. This might help:

https://www.gmupfitter.com/files/media/photo/139/2003_LD_SpecialApplications.pdf


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## JAJA (Dec 15, 2013)

update again...sun roof fuse is there and good so not the problem..looked at gm outfitters and didn't really find anything that would get me anywhere.. those who are new trying to help here is the story. Got the blunt cut wires from above the headliner put a plug on it and plugged the brand new beacon light into it nothing bench test light works fine, put test light on plug truck side no power, new relay no difference, check fuses, Seo b1 stud #2, sunroof and Seo b2 all good. Test light on relay white wire power when dash button is pushed, ground good no power on orange wire, traced orange wire to MBEC (mid buss electrical center)(by brake pedal) no power at pin that the orange wire comes from. have not been able to find where this orange wire gets its power from or anything close to a wire diagram of this MBEC, any ideas what to test next would be great


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## mkwl (Jan 21, 2005)

I had the same issue on my '03- read someplace that there was a relay or something like that missing under the dash, with it in place, the button would work. If I recall we popped a fused jumper in somewhere and it worked- this was like 6 years ago so it's a little fuzzy but I do remember there was definitely a piece missing from the factory.


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## joshg (Nov 12, 2009)

Look at A24-A27 in this one for more info. Info on B8 for the MidBec, C1 for the MidBec Connector, there is the whole wiring diagram in the doc too...looks like D165

Doc says for 2003 and beyond.

http://gmupfitter.com/files/media/photo/123/2004_LD_CKFullSizeElectrical.pdf

If you check and see what RPO code you have in the glovebox...maybe that would help? I want to look at mine now and see what applies to me.


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## JAJA (Dec 15, 2013)

Thanks for the extra info I will try to figure it out more researching to start


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## JAJA (Dec 15, 2013)

So haven't had time to work on this. So tapped into that power wire for the relay (orange wire) powered it off my own accessory power setup I set up and all good. Now I just need a bracket for the Whalen light I bought to hold the magnet and I will be good to go


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