cknaffle on ZR2.com wrote:
After hours and hours of trial and error and searching through tons of web pages, I found the combination that works for everything on my truck so I have total control of my lights. This post will tell you how to override your AHL (automatic headlights that come on in the dark), override your DRL (daytime running lights that come on when you put your truck in gear) and still retain your quadbeams (high and low beam headlights lit at the same time when the brights are on).
I am not taking credit for any of this work, I just want to put it all in one spot so it is easier to find. This information has been posted numerous times by numerous people, so don’t let me step on anybody’s toes here. Some of the old posts on this information seem to be lost and have inactive links in them, so hopefully this post will cover it all.
First, the quadbeam mod.
If your DRL are low beams and you want to just have quadbeams, and nothing else, simply take out your driver’s side headlight assembly, tap into the yellow wire with another wire about 12” or so long, put a ring terminal on the end of the wire, and ground it (either via a self-tapping screw or using an existing bolt). It’s that easy.
If your DRL are high beams, then go here http://www.s-10crewcab.net/HenryJ/quad.html
and follow the instructions to wire in a relay.
Second, the DRL disable mod.
On older trucks, all you have to do is yank a fuse out. Can’t get much easier than that. Sorry, I don’t know which one, but your owner’s manual should tell you.
On the 1998 – 2000 trucks, go here http://www.geocities.com/zq8gmcsonoma/drl.html
and follow the instructions. All you have to do is remove a relay and bend a tab back – about a 2 minute job at the most. My word of advice, when you try to take that relay out, use a large pair of channel lock pliers to get a hold of the base of it. It comes out very hard.
On 2000 – current trucks, go here http://184.108.40.206/cgi-bin/ultimatebb ... 2;t=000074
or here http://www.higherpowered.net/zr2/docs/drl2.html
It’s as easy as pulling the carpet back, finding a little relay taped to the wiring harness behind the brake pedal, and cutting the center yellow wire. Credit for this one goes to ZR2.com member James C. Thanks! If you want to be able to turn your DRL disable mod on and off, then just interrupt that yellow wire with a switch and put the switch somewhere accessible. If you want to get really fancy, then you can use that yellow wire coming out of the relay as a signal wire for another relay, then tap into the circuit for your parking lights, fog lights, or accessory lights. I’m not going there, I just hit the switch when I want them on.
Now the complication that held me up for so long. If you have quad beams and do the DRL mod, it will not work. It was as if you could only have one of the other. Here http://220.127.116.11/cgi-bin/ultimatebb ... p=1#000000
is the solution, as posted by ZR2.com member Jacob. Thanks! Buy yourself a relay, some splice connectors, and some female spade connectors. Pull out the driver’s side headlight and connect your relay like this. (85)is triggered by the high beam positive (green/white wire). The relay supply (87) goes to ground. The relay load (30) goes to the low beam yellow wire. The other relay trigger contact (86) must go to the high beam negative (purple wire) and NOT to ground.
Third, the AHL mod.
Take the speaker cover off the speaker on the dash on the passenger’s side. You’ll see a little sensor there. Take the wires off the sensor (a little clip holds it in place), and put a 680 ohm resistor in there (one wire from each side of the resistor goes in each wire’s hole. You can get the resistor at Radio Shack for under $1.00. This tricks the truck into thinking it is light out all the time.
I’ve seen the question asked before. WHY? For me, the main reason for the DRL & AHL mod is because I run Sylvania Silverstar bulbs, which are about $20 each. They put out amazing amounts of light, but they only last “up to” a year. I have yet to see a year out of any of them because they are always on with my DRL, and when I use the remote start on my truck (or whenever you start your truck at night), as soon as the ignition is activated by the remote, the AHL circuit turns the lights on (during the 3 second delay while the fuel pump is building pressure), then the motor starts while the lights are on. This little voltage flicker is not good for the bulbs at all. The reason I did the quadbeam mod is simple – MORE LIGHT AT NIGHT! Just don’t be an @ss and leave your bright on when you are passing people. [NoNo]
Let me say that I think everybody should still drive with some sort of light on. I personally run my parking lights and my factory fog lights during the day. I just like to be able to turn what lights on I want, when I want to do it. [Big Grin]