2004 Blazer headlights wont come on at night

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

Probly the wiring to it has resistence from wear. Or the switch

Did u ever figure it out ? Mine are doing same thing only work during the day and shut off when I turn lights on and don't work at night. I've changed all fuses and relays, still doing the same thing. I'm hoping it's not wiring issue

The headlight bulb is defective.

replace the headlight relay in the engine compartment relay box.

Check that your headlight switch is not on. They have an automatic dimming feature for night driving that reduces glare from the instrument cluster.

There is a light sensor on the front of the dash by the windshield.You should still be able to turn them on manually?

I would check the connection at the bulb. Check the wires and connector by wiggling them with lights on to see if they go off. Sounds like loose wire at connector. Daytime running lights are on a separate fuse and wiring.

it dims so u wont get blinded from the lights

Try to futz with the dimmer switch for the interior jiggling it see if you get them to even flicker.. if that's it then replace the switch. this happens often to. Check your relays make sure they are OK. Take a gander for burnt wires ETC down there etc. im not to sure as to how to do this but look in your driving manual and see how you change the light settings and try turnning the lights back to manal and see if that helps.. if that helps its the sensor on the dash thats causing the confusing.