Day time running lights
 

My day time running lights won't work but my headlights and taillights come on with my light switch off. This is on 99 chevy Silverado

My 1998 K-1500 doesn't have DRL's. Instead, the headlights come on at reduced power. I really like that function since I use lights on day or night. If need be I can pull the fuse, or easier, just click the parking brake foot lever down on notch and the headlight are off.

Check your DRL light bulbs and sockets. When I had my 99 Silverado the DRL light bulbs would burn out every so often. There was also so much heat there that the sockets occasionally melted some causing a problem.