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Auto Headlight Disable

 
 
 
 
  #1  
Old 03-14-2008, 06:04 AM
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Default Auto Headlight Disable

There is an easy way to Disable the auto headlights on Any 01-02(Includes Silverado, Suburban, Tahoe, Sierra, Yukon, Yukon XL, Denali, Denali XL) truck that only involves about 15 minutes of tinkering.

First of all you will need one 1.5kOhm resistor and some skotchloks or T-taps From Radio Shack.

Then after having all the parts it takes a few easy steps:

First step is to lay down on the driver side floor and look up under the dash at the mess of wires.

Next locate the BCM (Body Control Module)

the BCM will be a black box with Brown, Light Blue, and Purple connectors sticking out of it.

Now what you want to do now is disconnect the Purple connector (C3) from your BCM and spread out the wires to see them better.

Look at the C3 connector and locate the White wire (located in slot A6) and the Gray wire (located in slot A4)

If you are unsure about what wires are what here is the list from left to right....Top row: Pin A1(Dark Blue/White), A2(Dark Blue/White), A3(Brown), A4(Gray), A5(gray), A6(White), A7(not used). Bottom row: N/A for this modification

With the wires identified you can Jump the two wires with the 1.5k ohm resistor using some spare wire, tape, and skotchloks.

make sure you tape up the exposed wired and resistor to eliminate the chance of shorts.

After tapping the white and gray wires connect the C3 connector back to the BCM and your mod will be complete.



To test out, on a sunny day throw a towel over the ambient light sensor on your dash (The little bulb sticking out in the top of your dash near the windshield) and see if your lights come on....if they don't come on success!



/me was so bored he decided to open up his service manual and look up the Headlights/DRL schematics and tell the world about this awesome bomb....
 

Last edited by 2500HeavyDuty; 03-15-2008 at 07:50 PM.
  #2  
Old 03-14-2008, 10:16 AM
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thats good to know good thing the 03 came with a switch though
 
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Old 03-14-2008, 10:20 AM
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Originally Posted by toy4xchris View Post
thats good to know good thing the 03 came with a switch though
You can turn off the lights with the dome override switch by pressing it 4 times, but if you got HID's installed its good cause it will save them, and you can sneak around...
 
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Old 03-14-2008, 10:28 AM
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uuummmm....Danno, you forgot a VERY important piece of information.

If you guys are going to do this mod DISCONNECT THE BATTERIES. The BCM is very sensitive to voltage and current changes and has a small 10ma current to it at all times. If you short or cross some wires while doing this mod you will disable all controls in your truck.
 
  #5  
Old 03-14-2008, 11:19 AM
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Sounds like you speak from experience
 
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Old 03-14-2008, 01:40 PM
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Fried a few BCMs before DD?

I never un hooked my battery on my truck, but I did remoce the C3 connector out of the BCM before I started workin on it. The the Gray wire has a 5 volt current going through it and goes into the ambient light sensor. And comes back through the white wire back into the BCM....IIRC I'm @ work right now.

But T is right you should disconnect BOTH batteries before messing with the BCM, to prevent accidentally shorting it.
 
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Old 03-14-2008, 01:42 PM
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uuummm....NOOOOOO.
 
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Old 03-14-2008, 01:58 PM
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Who's then?
 
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Old 03-14-2008, 02:02 PM
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uuummm...I'm not completely sure but I do know it WASNT my truck.
 
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Old 03-14-2008, 02:21 PM
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Atleast you didn't screw yours up.


Does anyone have the Wireing diragram for 03 and up trucks? The Mod is verry simmilar but I don't know what wires are which.
 

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