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Fog lights on Silverado 2500

nestlocknestlock Member Posts: 1
edited March 2014 in Chevrolet
I am the proud owner of a 2000 Silverado 2500 EXT
SB. So far I love the truck. It just turned 400
miles last night and got 13 MPG on it's first tank.
I hope it gets a little better. It has the Snow
Plow Prep Package, which gives it an Auxiliary
Light switch on the dash next to the Passenger Air
Bag On/Off switch. I want to install fog lights in
the spaces provided and I want to use the
Auxiliary Light switch to turn them on and off.
Does anybody out there know where the wires are
that come from this switch and if there is a relay
in there, or not.
Does anybody have any tips on what kind of
lights to install or any tips on the installation


  • tubeking1tubeking1 Member Posts: 6
    I have the same question Don. The dealer at purchase time told me he thought they were under the cmbl for powering a strobe. Hope you get a answer as id like to do the same thing.
  • vince4vince4 Member Posts: 1,268
    I also have a 2k 2500 but with fog lights and without plow prep. I do have the factory service manuals so I spent some time looking through the wiring sections today.

    I couldn't find any switch marked as part of that option. There is a likely suspect though, the Roof Beacon switch. They don't have a picture of the switch but it says it's located in the middle of the instrument panel. It appears to be an illuminated switch, is yours? The switch runs a relay located either at the left B pillar or under the driver's seat. They aren't clear between SUV and pickup. The relay output wire and a ground wire come off to a blunt cut. They aren't connected to anything and it doesn't say where they are but it seems obvious that they would be in the roof.

    If you want to use that switch for your fog lights you are best off cutting its output wire under the dash and using that rather than trying to use the roof beacon relay output. If you want a copy of the schematic send me an e-mail and I'll scan it.

    The snow plow package also comes with an extra connector in the DRL wiring up front. I guess that is so you can have high mounted DRLs on the plow.

    The GM fog lights are really lame, don't buy them. They aren't very bright. PIAA makes a nice set made for those holes which include a fog and driving light in each housing. I'd love to switch mine out however the PIAAs cost over $300. Maybe I should sell you my factory lights. If you find a good aftermarket set that fit those holes nicely let me know.

    BTW tubeking, what is cmbl?
  • tubeking1tubeking1 Member Posts: 6
    Mister lazy here, center mounted brake light, or do they call it the cmhbl / hi brake light.? Something like that anyway.
  • mledtjemledtje Member Posts: 1,123
    I think the official name is CHMSTL (Center High Mounted Stop Light).

    Of course, mine is covered by the camper and only visible in my rear view mirror as it reflects off the camper.

    Mike L
    00 2500 LS 4x4 Reg Cab Longbed 6.0L 5spd
    Deadhorse, Alaska 6-6-99
  • vince4vince4 Member Posts: 1,268
    Well Don did e-mail me and sent a photo of the switch. It's labeled "Aux Lights" which I'm guessing is generic so they can use the same switch for multiple options. I couldn't find anything other than the Roof Beacon switch in the manuals.

    Why would GM put an additional connector in the DRL wiring and give a switch for a roof light? It seems like the additional lights you would want are high mounted headlights above the plow with their own switch. Who cares about DRLs when you are likely to have your lights on anyway in the snow. Maybe the manual just doesn't show the real switch function. Does anyone know? (I'm curious now)
  • nyalnyal Member Posts: 17
    The switch is part of the plow package and is in fact for a roof beacon.
  • vince4vince4 Member Posts: 1,268
    I'm glad to see the manual is correct anyway.
  • careyacecareyace Member Posts: 44
    If anybody needs help finding the wires let me know as I found them.
  • vince4vince4 Member Posts: 1,268
    Yes, tell us about the wires.
  • careyacecareyace Member Posts: 44
    I have a 2000 2500 LT ext. cab 4dr with snow plow prep package and have that switch that does nothing;so I went to the dealer I bought it from and after about three hours of service manual and a computer and a phone call to the factory rep. still no answer so I went home to look on my own.

    The switch seemed to have power with the key in the off position.When I pushed the switch a few times and there was the click of a relay and so I tracked it down.The relay was in the left rear corner of the cab behind the plastic trim.The wires from the relay go up to the roof and no you cant see them from the high brake light nor the interior light.The wires are coiled up almost directly above the drivers head rest above the ceiling liner and the are just pig tails with tape on them.

    After I found them I went back to the dealer to talk off road lights/fog lights and they said there is enough power to run an average set of lights.

    Sorry about the whole story but I to researched this for some time.

  • z71z71 Member Posts: 67
    if you can order this switch from the dealer? I thought about ordering it and using it for my reverse lights. Do you think that it would plug right in or what?
  • erikf2erikf2 Member Posts: 100
    I measured the opening for the flash-lights (excuse me, I should say "fog-lights" since most flash-lights are actually brighter than these things) on my '00 2500 this weekend and came up with approximately 7.5" wide by 3" tall (best case measurement; the "elongated-D" shape of the opening could reduce the width up to an inch). After going to the Hella and PIAA Web sites, i came up with the following rectangualr PIAA models that should fit the opening: 1500 series, 930 H.I.D., and 980 Dual System. Vince, I think you were referring to the 980 Dual System in post #2.

    Has anybody had any experience with PIAA systems? Are they any good? Also, the 930 H.I.D. uses a 35W bbulb, the 1500 series uses a 55W bulb, and the 980 Dual System uses two 55W bulbs; are the factory wires adequate to the increased current? Finally, the auto parts place I went to had what appeared to be a bunch of PIAA clones made by a company called Pilot. Has anybody had any experience with their products?
  • careyacecareyace Member Posts: 44
    You can probably order the switch but the plug and relay will not be in your truck.
    I used to have a 1996 ext. cab Z71 and had four off road lights on the grill guard so I ordered two switches similar to the aux. switch in the silverado.The difference was mine were square and the had FOG LIGHT back lit on them. What I did for plugs for them was solder wires to the pins on the back of the switch.You just need to figure out what each pin does so you know where to wire it,and there were five pins.The switch I had went in the dash next to the push button 4wd but I built them into a nice home made center council I built.The switches were $25.00 + each.

  • vince4vince4 Member Posts: 1,268
    Andrew, thanks for the wire information.

    I do like the 980 dual PIAA lights but haven't crossed the price barrier yet. I'm sure the factory wires are just fine for a 55W bulb. 20W additional is less than 2 extra amps and they don't fine tune the wiring to that extent.
  • mledtjemledtje Member Posts: 1,123
    I also like the 980 dual lights. I'm not too sure about running the extra wiring for the 2nd light, but it would be nice to have both (real) foglights and driving lights.

    Then the stock, wimpy foglights would be available as backup/area lights behind the truck. They should light up the whole camping area, especially when they are mounted up high.

    I sold my El Camino, so I have a couple of extra bucks.

    Mike L
  • meredithmeredith Member Posts: 575
    After 30 or more days of inactivity....

    this topic is being "frozen." It will be archived or deleted in the next 10 days or so.

    Front Porch Philosopher
    SUV, Pickups, & Aftermarket and Accessories Host
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