01' Headlight switch question????

[Shed]

I bought my 01' a couple of years ago with 65k on her. I have always had an issue with the light switch. No matter what the lights are "on". I cannot simply turn the lights off and just let it sit there idling in the dark. Why???? I notice this on our long trips with the fifth wheel, running after dark and a semi passes me. I go to flip the lights off and on to let him know it's o.k. to move over and I get nothing! I have forgotten to turn on my lights and simply driven with the switch in the off position. The dealer tells me this is how the truck was made. What? I had a 00' gasser and that was not how the lights worked on it... Any thoughts? I'm thinking maybe a bad switch? How difficult is it to replace that switch? I know what everyone is thinking, what a dumb thing to gripe about.... I apologize, it's always the little things with me! Thanks for any ideas/help! Shed

[DmaxMaverick]

That's how they work. I don't know when they changed them, but they all have it since 2001. That little "pencil eraser size" black button in the middle/front of the dash (in the defog vent) is the photocell, which senses day/night (or sufficient darkness). If the lights are on even in the daytime, check that sensor for something covering it (dash rug, paper, lots of dust, bug, etc.).

You can defeat the "auto lights" by pressing the dome override button 4 times within about 5 seconds. You should hear the chime, and the lights go off. This will also defeat the DRL's and instrument panel/dash dimming (bright lamps, all the time, with gage lighting off). It will reset back to normal once the ignition is cycled, or when the button is pressed 4 times again. The headlamp switch will then work like traditional lighting, fully manual. If you want to start with lights off, set the E-Brake (before turning the key to on). The headlamps will stay off until the brake is released.

If you replace the switch, you'll get the same thing (the control is in the BCM, not the switch). The only way to permanently defeat it is to shunt the photocell (or the circuit), or reprogram the BCM (police option vehicles have this disabled in the programming). Canadian vehicles have the same feature, only they are unable to defeat the lights, at all. The E-brake defeat may work with them, but that's it.

[Shed]

Thanks Mav! That was all I needed. Just a "shut up and deal with it". This must be some sort of safety device.