I own 2000 chevy z71 truck and in the last week my headlights come on during the day time even on sunny days instead of day time running lights. Nothing on my dash to block sensor on dash.

assuming the 2000 is same as 2001-2002, the headlight system runs upon firing engine and they stay on... doesn't make sense , if headlights work during day light and don't during night time,check your light switch , move it around , wiggle etc.. if no diff. , check head light sensor and did you know there are like 3 or 4 diff. fuse box's , there is one in the dash!!!, driver side i believce , good luck

This is lest ;plugs,wire,coils.

To disable the drl/auto lights press the dome override button 3 times.a chime will sound once you've successfully done it to let you know.

Check the emergency brake pedal and make sure it is not on a bit. When the emergency brake are applied the daytime running light go out.

I have a 1997 chevy 1500 350 4x4. My problem is that I can not get my headlights to work. I have checked the fuses inside the truck and under the hood. They are all good. My side markers work, my tail lights works, and even my day time running lights work. The only thing that doesnt work is the headlights. If I turn my head lights on my day time running lights turn off. Does any one have an idea of what could be causing this.

there is a small sensor on the dash of your truck if this is covered or excessively dirty it will keep your auto lights on. if you press the dome light over ride button in and out three times this will turn your lights off.

This code can come from a variety of problems. Could be a bad O-ring, or a shift solenoid, even worn clutch rings. Could even just need a computer update/reprogram. Unfortunately its not an easy diagnosis because of the wide range of possible causes. You are probably going to have to take it in.

There is a light sensor that tells the truck if it is night or day on the dash. Make sure that is it not covered up. If is is not then you may have a bad sensor. It sounds like the sensor is telling the truck that it is night every time the truck is running.

Start the tuck with the park brake on to see if the light come on when it starts. If they do you have a bad relay if not it is most likely that sensor on the dash.

The day time running lamps are your headlights, the parking lights also conventionally known as the running lights serve no purpose during daylight hours and as such are not necessary in the daytime, and are not illuminated by the DRL module. The DRL (Daytime Running Lights) module illuminates the headlamps in a slightly dimmer state than night time dim headlamps, but does not turn on the conventional running lights. The only way you'll get conventional running lights during the day is to turn them on manually. I just reviewed the wiring schematics for that system, and the DRL relay bypasses the dimmer switch when active and prevents high beam operation, and feeds current directly to the low beam headlights, there is no connection to the parking light circuit from the DRL module wiring.

When you say you replace the fuse 3 times, is because the fuse have blown? If so, there is a short in the system and will need expert help to trace the short.
Does the day time running light stay on during day light hours and does the lights comes on without activating the headlight switch during night hours when the park brake is released?
If so, this of course is normal condition. If not then the day time running light circuit needs diagnosing along with the body module circuit. Headlight switch will also need to be tested.