Thanks For Your Post, Chuck 16

gm4yrs · June 3, 2008

Chuck 16, I read your post at automotiveforum.com, last year, and wanted to thank you, for the simple wiring diagram, that you posted. I have a lifted truck, and have been blinding small cars, for years, at drive-thrus and at stoplights. On 99's, you could not, turn off, those headlights, at night. No dome override option for me. So, I installed a switch, under the dash, and now have control over the headlights. Again, thank you. Bruce

chuck16 · June 4, 2008

Hey Bruce,

Your more than welcome. I remember when I first got my truck and I was backing it into the garage when all of a sudden all the lights came on. I thought Oh great now what. I then realized that it had automatic lights. As cool as it is I still like having the manual control.

SO I'm glad the following diagram helped you out:

Cheers

Evan

Jackson · June 4, 2008

you didn't have to install a seperate switch. an inline ohm resistor would have done the trick. I'll post the details here shortly.

EDIT: I see he was talking about an ohm resistor as well. not sure why you needed an extra switch then?

This is copied from gmfullsize.com

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!

here is the thread

http://www.gmfullsize.com/forum/showthread.php?t=98683

worked like a champ for me and now I can use my factory switch like it was intended.

chuck16 · June 4, 2008

I put a switch in called the Wife Switch. So that when she borrows the truck she doesn't have to worry about it. When I'm not using it I flick the switch into Auto when I'm not using the truck. FYI - The resistor goes parallel not inline in that setup.

gm4yrs · June 4, 2008

Hey Bruce,

Your more than welcome. I remember when I first got my truck and I was backing it into the garage when all of a sudden all the lights came on. I thought Oh great now what. I then realized that it had automatic lights. As cool as it is I still like having the manual control.

SO I'm glad the following diagram helped you out:

Cheers

Evan

Evan, I'm glad you seen my post, and thanks for the reply. I like the automatic headlights, but put up, with no control, to turn off, when needed, for 7 years. I went to the stereo shops and even called gm, for a solution to my problem. No one helped, or didn't know how, or wanted to. So, when I seen your post, it was great info. to find. I printed it out and fix it the next day. I remembered your sign name and found this forum, and seen, that you were here too. So, I had to tell you, thanks. I don't think enough people do, when someone else helps out. Also, there are other ways to disable, all together, the automatic headlights, But I like this one.

Gitingrdone · June 5, 2008

in my truck when the auto headlights come on i hit the dome override button about 4 times then it "bings" and they go off. It works with the daytime running lights too. Then i have manual control. It doesnt have that new switch where you hold it to the left and they are disabled. I thought that was neat. I kinda figured that out on my own trying to see if that button was pushed in or out. And i noticed if you start it with the emergency brake on the auto lights are disabled.

gm4yrs · June 5, 2008

in my truck when the auto headlights come on i hit the dome override button about 4 times then it "bings" and they go off. It works with the daytime running lights too. Then i have manual control. It doesnt have that new switch where you hold it to the left and they are disabled. I thought that was neat. I kinda figured that out on my own trying to see if that button was pushed in or out. And i noticed if you start it with the emergency brake on the auto lights are disabled.

On 1999's only, there was no dome override, on/off, function for the headlights. I do have the switch, below the headlight manual switch. Just not the function. I have heard, if you replace the body control module to a 2000-2002, it then will work. You will also get programable door locks for 4 options. 1999's would lock at 15 mph. and then you would manually, have to unlock, to get out. I fixed that, with an aftermarket alarm, with programmable door locks. Before I found chuck 16's wiring diagram, I would have to turn the truck off, click the parking brake a few clicks down, and then restart the truck, at a drive-thru for instance. Then, the lights were off, and could be controlled by the headlight switch on the dash. Since you don't want to drive around with your parking brake engauged, this was, my only solution, to the problem, for 7+years.

Jackson · June 5, 2008

I put a switch in called the Wife Switch. So that when she borrows the truck she doesn't have to worry about it. When I'm not using it I flick the switch into Auto when I'm not using the truck. FYI - The resistor goes parallel not inline in that setup.

gotcha. just spreadin more of the info around.