Auto Headlight Questions?

Jim GMC · October 8, 2008

I read somewhere that if I hit my dome override button 4 times its supposed to turn off my auto-on headlights but it doesn't work on my truck, a 1999 Sierra SLT. Is there a way to turn them off? I am not looking to turn them off everyday, but it is nice to know that I am able to actually turn them off if I want to one day. Also, on my friends 06 Silverado W/T the auto headlights stay on for about 10-15 seconds after he turns off the truck. Is my truck supposed to do that? When I turn off my truck the lights turn off as soon as I turn the key, is there a way to change that?

Jim

2000DV4.8 · October 8, 2008

The '99s didn't have the auto headlight override feature, it started with the 2000 trucks. As far as I know, the only way to disable them is permanently.

Jim GMC · October 8, 2008

The '99s didn't have the auto headlight override feature, it started with the 2000 trucks. As far as I know, the only way to disable them is permanently.

Well that sucks. Since the 99 NBS and 00 are basically the same, is there a part I can swap out to make it work?

2000DV4.8 · October 8, 2008

It would be the BCM (body control module), but I don't know if it's possible.

I remember a thread about it a while ago, you might try searching while you wait for a more definitive answer.

Jim GMC · October 8, 2008

Thanks for your info. I saw a wiring diagram, but I don't want to go cutting wires incase I screw something up. I was hopping for just swaping out a differant headlight switch or something similar. Either way, are the headlights supposed to stay on after you turn the truck off or is that a newer truck option?

Also, I see you are part of the 170k+ mileage club, how many miles do you have? I have 171k or so.

chuck16 · October 8, 2008

Hey Jim,

It's real easy to do. You just need a 1.5 K ohm resistor and a couple of wire taps. Tap 2 wires across your BCM that go to your Auto Light sensor on your dash and voila!.

Let me know if you want a more thorough answer. It's like a 20 min job. Piece of cake. i even wired in a switch so I can return to full auto if I want.

-Evan

sonjaab · October 9, 2008

http://www.lightsout.org has the resistor wire mod/trick instructions on how

to disable the DRLs and auto ons.

chuck16 · October 9, 2008

Alright here yah go:

FOR '99-'02 TRUCKS ONLY w/o AUTO CLIMATE CONTROLS

Basically you will need a pair of wire cutters and a 1.5K ohm 1/2 watt resistor that you can get at Radio Shack. Electrical tape and possibly some wire nuts will work to wire in the resistor. You can solder the wires if you wish.

You may want to remove the neg. battery cable to assure you don't do any unwanted damage to the electrical system. This is not necessary, but a good precaution to take.

First locate the Body Control Module (BCM) which is under the dash, below the steering column. Laying on the floor, this should be visible without removing any dash panels. You should find a purple connector (C3). Unplug it.

Locate the white and gray wires (A4 and A6). I don't remember if white is A4 and gray is A6 or vice versa. It doesn't matter anyway.

Clip these two wires that are coming off this plug (C3). Leave a few inches to work with. Tape up or place wire nuts over the other end of these wires that go up under the dash(they go to the light sensor). You have now removed the light sensor from the electrical system and is now just a dash ornament.

Connect the gray wire from the plug (C3) to one end of the resistor and the white wire to the other end. Make sure you tape up all wires to prevent a short. You should now have a gray wire coming from C3, going to one lead of the resistor and the white wire from C3 to the other resistor lead. Plug in C3 to the BCM and replace the neg. battery cable if you removed it. Start the truck and make sure the lights are off. Throw a dark towel or something over the light sensor on the dash and verify the lights stay off. Try your light switch that has probably never been used and that's it!"

Jim GMC · October 11, 2008

Thanks for the responses. I was wondering if anyone put a newer style headlight switch (the one that has a setting for auto) into a 99 p/u. I do like the idea of still having the option for auto headlights if I want to use them.

slayer305 · March 18, 2009

I know this is a older thread but I have some questions that weren't really answered. I have a 2000 and according to some posts it should have the 4 way headlight switch. Off, auto, parking, and on. Mine only has the 3 way. Auto, parking, and on. Mine is a later built 2000 as it has 4 doors instead of 3. My theory was to find a 4 way switch and change it out to see if that worked. I like the feature of the auto head lights but when I pull into a driveway or parking lot and dont want my lights on I want to be able to control them. Does anyone know if that will work?

chuck16 · March 18, 2009

Why don't you just wire it like my diagram is and that way you don't have to replace the switch. You just have a little micro switch that does the extra step that switches from Auto to Regular Control?

A micro switch and a 1.5 K ohm resistor should only set you back about $5 whereas a whole new GM Switch could be $50 or so??? I mounted my Micro switch down next to the OBD2 Reader so if I want it in Auto Mode I reach down and take the resistor out of the loop and if I want manual control I just flick the switch in the other direction.

I just went to Rockauto and I don't actually see a 4 position switch all the way up to 2003 so I'm not sure where you've seen a 4 position switch????

Just my 2 bits is all..

Evan

mr_bots · March 18, 2009

I know this is a older thread but I have some questions that weren't really answered. I have a 2000 and according to some posts it should have the 4 way headlight switch. Off, auto, parking, and on. Mine only has the 3 way. Auto, parking, and on. Mine is a later built 2000 as it has 4 doors instead of 3. My theory was to find a 4 way switch and change it out to see if that worked. I like the feature of the auto head lights but when I pull into a driveway or parking lot and dont want my lights on I want to be able to control them. Does anyone know if that will work?

The didn't add the 4-way switch till 03, before than it was just 3-way and to turn off the lights or DRLs you had to hit the dome override 4 times (2000-2002). I don't know how much of the electronics will switch. They made a lot of changes to the electrical systems for 03.

slayer305 · March 18, 2009

Why don't you just wire it like my diagram is and that way you don't have to replace the switch. You just have a little micro switch that does the extra step that switches from Auto to Regular Control?

A micro switch and a 1.5 K ohm resistor should only set you back about $5 whereas a whole new GM Switch could be $50 or so??? I mounted my Micro switch down next to the OBD2 Reader so if I want it in Auto Mode I reach down and take the resistor out of the loop and if I want manual control I just flick the switch in the other direction.

I just went to Rockauto and I don't actually see a 4 position switch all the way up to 2003 so I'm not sure where you've seen a 4 position switch????

Just my 2 bits is all..

Evan

Evan

I have a few questions before I attempt this. You said to clip the wires to the sensor? Actually cut them and add the resistor into the harness, and the wires for the sensor go away, or just tap into the wires? Also if you used a switch how did you wire that in? Didnt see it on the diagram that you have.

Thanks!

chuck16 · March 19, 2009

Why don't you just wire it like my diagram is and that way you don't have to replace the switch. You just have a little micro switch that does the extra step that switches from Auto to Regular Control?

A micro switch and a 1.5 K ohm resistor should only set you back about $5 whereas a whole new GM Switch could be $50 or so??? I mounted my Micro switch down next to the OBD2 Reader so if I want it in Auto Mode I reach down and take the resistor out of the loop and if I want manual control I just flick the switch in the other direction.

I just went to Rockauto and I don't actually see a 4 position switch all the way up to 2003 so I'm not sure where you've seen a 4 position switch????

Just my 2 bits is all..

Evan

Evan

I have a few questions before I attempt this. You said to clip the wires to the sensor? Actually cut them and add the resistor into the harness, and the wires for the sensor go away, or just tap into the wires? Also if you used a switch how did you wire that in? Didnt see it on the diagram that you have.

Thanks!

Slayer,

Just use 2 "hop clips" I'm not even sure what they're called but they snap on to the existing wire so that you don't have to cut the old wires and leave everything the way it's suppose to be.

The switch just goes inline with the resistor. In the diagram the break in the line to the resistor indicates a a switch. If I get some time on Thursday i'll take some pics of it for you.

So to quickly answer your question you don't need to cut any wires just "tap" into them. That way you can still use the auto sensor if you wish.

-Evan

slayer305 · March 19, 2009

Why don't you just wire it like my diagram is and that way you don't have to replace the switch. You just have a little micro switch that does the extra step that switches from Auto to Regular Control?

A micro switch and a 1.5 K ohm resistor should only set you back about $5 whereas a whole new GM Switch could be $50 or so??? I mounted my Micro switch down next to the OBD2 Reader so if I want it in Auto Mode I reach down and take the resistor out of the loop and if I want manual control I just flick the switch in the other direction.

I just went to Rockauto and I don't actually see a 4 position switch all the way up to 2003 so I'm not sure where you've seen a 4 position switch????

Just my 2 bits is all..

Evan

Evan

I have a few questions before I attempt this. You said to clip the wires to the sensor? Actually cut them and add the resistor into the harness, and the wires for the sensor go away, or just tap into the wires? Also if you used a switch how did you wire that in? Didnt see it on the diagram that you have.

Thanks!

Slayer,

Just use 2 "hop clips" I'm not even sure what they're called but they snap on to the existing wire so that you don't have to cut the old wires and leave everything the way it's suppose to be.

The switch just goes inline with the resistor. In the diagram the break in the line to the resistor indicates a a switch. If I get some time on Thursday i'll take some pics of it for you.

So to quickly answer your question you don't need to cut any wires just "tap" into them. That way you can still use the auto sensor if you wish.

-Evan

Got it! I just wanted to make sure before I did anything. So far I may not tackle it though. The dome over ride button works for me. It would maybe be nice if I wanted to start the truck and the lights not even come on though.