So I have a 04 Blazer ls 4x4 ( Not Trailblazer ), I wanted to do the quad beam mod and after reading endless pages I am really confused to what the solution really is.. I grounded the yellow wire on the drivers side low beam and tada the quad beam worked.. all good right? Nope. my DRL's are also quad beam now and not so legal in Pennsylvania. So I popped the DRL relay out and Yep I still have DRL's in quad format.. . if anyone actually knows the how to on the 2004 with High Beam DRL's please chime in.

on a similar note, I picked up some 1998 front turn signals with the fog light inserts and wanted to connect them up also.. in my state fog lights can only be active with low beam selected. So I'm also looking for a schematic on how-to wire this up so they only can come on with the low beams.sounds easy enough but dang me I've tried and because the way the lights are switched with grounds and such I just cannot make it work correctly. If you know a verified way to make this happen, please send me the wiring diagram.

 

Disabling your DRLs is probably your best bet. Lot's of info on this site about that. On my 98, I had to bend pin #86 on the DRL relay so it made no connection. (I grabbed an extra from the junk yard, cut the pin, and kept my original intact.)

 

On my 04 I did the quad mod by grounding the wire. I also tried to disable the auto headlights with the resistor in the plug for the light sensor, and it just didn't work for some reason. So I took the resistor back out and just plugged the sensor in, my auto headlights come on 99.9 percent of the time, every once in a while they don't if the sun hits the sensor just right I guess... I gave up and just hit the dome light button 4 times every time I start the truck... My only hope is to get someone with a Tech2 to turn off the auto lights in the BCM. Or rewire the headlights completely to only operate off the switch, which is what I WANT to happen...

 

okay but what about the extra housing in the headlight as used by the Bravada. I'm speaking of the lower inner case below DRL high beams. is it the same housing is the Jimmy where that is the in-house fog light? because my Bravada Factory fogs are under in the cowl. can I splice in extra Amber's to those spots?

 

There's no hole there, you'd be better off getting a set of Blazer/Jimmy assemblies with the fog lights and doing it to those if that's you'r plan. They will drop right in place of the full amber assemblies. I installed and ran some for a short time with the intentions of wiring them up as fog lights, but in the end just installed aftermarket projector fog lights...

 

The correct (and easiest) way to do a quad beam mod on your truck is to put a diode across the grounds between high and low beams. Just find the ground wires at the bulb plugs on the driver side and solder in a sort length of wire and the diode (1N4005).

You’ll need to disable the ridiculous drl circuit by bending the pin as described above.

I’d also strongly recommend wiring in a set of relays for the high and low sides if you intend on making any other improvements to your lighting

 

99-
A few months old but had a question I couldn't find answer to elsewhere on wiring. I swapped out OEM radio and replaced broken bezel which came with light switch. Switch had fog lights so as next project thought about adding OEM fog lights. I bought a salvage BCM from a Blazer with fog lights and now need wiring harness. Reading posts it is unclear (to me at least) if I need a completely new wiring harness from switch to lights or if you can just splice in pigtails for fog lights near head and parking lights. I'm planning on buying new integrated parking /fog lights so didn't get them from PNP.
Thanks, Kevin

 

When I swapped my dash from "grey" to "black", I had to swap the entire harness because it didnt have the right 4x4 switch nor the wire for fog lights.

not sure if this helps, but I'm thinking you'll need the wire harness, and the harness under the hood... might be easier to wire in on an after market toggle switch. Unless time is of no mater...