Fog light harness

[CDJuda]

I think I posted awhile ago but I'm having trouble finding a harness that would work with the fog lights I ordered. I have the housings, brackets, and lights, just can't find a harness that would work with a switch.

I would need a switch because I have the quad beam mod and having more than 4 facing headlamps at once is illegal.

Thanks guys!

 

[The_Roadie]

You mean a hunk of wires with an inline fuse holder, relay socket and a switch? I'm astonished you can't find that. Where have you looked, and using what search phrase?

I'm seeing about 100 of the kits on Ebay right now from $13-20.

Every local parts store should have it. WALMART should have them.

 

[CDJuda]

Is item number 29 what I'm looking for? OEM fog harness and switch? I have the LS witch did not come with fog lights.

http://www.gmpartseast.com/Page_Product/PartList.aspx?MakeUrl=chevy&CatalogUrl=2004-trailblazer-4wd&ComponentCode=TS1624901&SectionCode=16&EngineCode=LL8&TransmissionCode=&ModelCode=T15506&Vin=&ProductionDate=&VehicleInfo=&CatalogCode=56S&Year=

 

[CDJuda]

I'm not a lighting guru, I'm having someone install the fog lights for me and the fog housings and brackets did not come with the wiring harness he needed. He said it didn't come with a harness so we kinda need one.

 

[The_Roadie]

Ahhhhh, missing information.

OEM fogs can ONLY be added to a vehicle that didn't have them by running your own aftermarket bypass harness, switch and relay. Look for them in your local aftermarket parts store. It will take a bit of electrical knowledge by your installer.

The OEM harness is built into the vehicle at the factory. Not worth swapping that. The OEM light switch with the fog lamp button doesn't directly control the lights as you might guess. The switch is wired to the BCM (body control module) under the back seat. And then if the BCM feels like it (other conditions need to be satisfied) it turns on the fog lamp relay that lights the fog lamps.

It requires a dealer to reprogram the BCM to even LOOK at the upgraded switch, and that usually kills the project for anybody who insists on using the factory switch. You will end up with a switch elsewhere on your dash to control your new fogs.

 

[IllogicTC]

If the switch were pure-analog (having a consistent on or off state) using the headlight switch with the button would be a lot easier. Instead we have a switch that is normally open. Closing the switch just makes the setting in the BCM flip states, if it's on now it's off, if it was off now it's on.

Though I am curious on the possibility of a sort-of workaround. I'll have to test and confirm, but the dome light defeat button feels like it's a "pure-analog." It's hard to feel, but it feels kind of like a spring-loaded toggle button with a definite on and off state. I ponder at the feasibility of tapping into the wire that runs to it to control a fog light relay. You wouldn't have to rig up a new switch somewhere then if you didn't want to (to help keep an OEM look), but you'll lose dome light defeat in the process. Or you could tap into the dimmer switch's analog switch functionality, though it'd be strange to be forced to turn your brightness all the way up to turn the fogs on, and you'll lose THAT function instead in the process.

 

[Hiway Diesel]

Take a look at this:

http://www.ebay.com/sch/i.html?_trksid=p4712.m570.l1313.TR0.TRC0.H0&_nkw=2002+to+2009+Chevrolet+Trailblazer+Fog+Light+Wiring+Harness&_sacat=0&_from=R40

 

[The_Roadie]

Interesting product. Has the right lamp-end connectors. Allows you to slave them to the parking lights. But for manual control, you still have to add your own internal switch. Doesn't use the factory push button and fuse block-located relay.

 

[Hiway Diesel]

You are correct sir! I have a 02 LS that I occasionally get interested in, and right now its in the spotlight. I researched trying to upgrade, but am not willing to let the goobers at the local dealer mess with my BCM to make a slipstreamed setup possible. So that harness with either a low beam trigger, or a discrete internal switch is the way I am going. The fogs have been in place far too long without activation lol.

I see you are a TB Master. Do happen to know anyone with a vinyl cutter file to make pillar overlays? I did a tryout of blacking out the pillars (plastidip) and decided to make it permanent. If no file is available, I will trial and error one on my cutter. Then I have to decide on matte or gloss black.

I have rediscovered plastidip. It makes a great temporary travel bra and provides the best tire UV protection for trailer/RV tires while stored. Truly a wonder product for outliers.