Question to ppl with HID's and Automatic Headlights

[TravisH]

I put the key in the ignition and the headlights come on and when you crank, they turn off for a split second and sometimes one doesn't or they both don't come back on.

Anyone find a work-a-round for this?

THanks,
Travis

 

[boostaholic]

You can wire up a switch or if the truck is pre-03 just keep the parking brake down. I think you can also deactivate and reactivate the auto headlights by depressing the dimmer overide switch 4 times.

 

[Botches]

you can switch back and forth by pressing that button. I have found that option helpful when the family goes to the drive-in movie, when we leave I turn off the lights so I don't disturb anyone.

 

[JKmotorsports]

I'll have to check which wires I tied into, but you can run a 1K ohm resistor parallel with the wires to the photosensor from the bcm. I'll see if I can get underneath the dash when I get a chance and find out which wires I used. Anyway, this will tell the bcm that it is still light outside and the auto lights won't activate. Or you can straight to the sensor and tie in there.

 

[TravisH]

i know about the override switch but i don't want to press it 4 times and then 4 times again.

Thanks JK, let me know what you find.

 

[boostaholic]

Found it on fullsizechevy, I'm sure there are some other writeups with pictures if you just google auto headlight chevy



To disable the auto headlights you need a 1.5K ohm resistor (Radio Shack) and 2 Scotchlok Tap Connectors (Walmart).

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. BTW - there are two gray wires in the connector. The one you want is the one farthest away from the white wire.

Tap the gray wire from the plug (C3) to one end of the resistor and the white wire to the other end. You don't need to cut the wires. Make sure you tape up all wires to prevent a short. You should now have a gray wire coming from C3 tapped to one lead of the resistor and the white wire from C3 tapped to the other resistor lead *. Plug C3 back into the BCM. 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! Takes about 5 minutes.

*You can add a switch here if you want. Just connect one end of the resistor to one of the wires in the connector (doesn't matter which one) and the other end of the resistor to one side of the switch. Then connect a wire from the other side of the switch to the other wire in the connector. This will allow you to turn Twilight Mode on and off.

 

[05LS]

I noticed that if you have a delay in when you turn the key from acc to on the lights come on, go off, then come back on when running. I usually just do one motion to turn the car on, haven't ever had any problems with it.

 

[TravisH]

Thanks for the info.

 

[TravisH]

I only wanted the auto headlights to not come on when I remote start so I made a circuit with the information using a relay. This is how to do it.


86 - Ground out when running from Remote Start
85 - +12 Volts
87 - Gray or white wire from BCM
30 - 1.5k Ohm Resistor and gray or white wire (opposite color of 87) from BCM