Updated cat eyes.
does anyone have a wiring schematic or know what each bulbs purpose is thanks.
i know the top is high and low beams. The bottom lens though has 3 bulbs. Turn and side marker/parking lamp. Other one?

 

The bottom lens assembly has the daytime running lights (DRL), turn and side marker/parking lamp. On my 2006 "cat eye" I am pretty sure the DRL bulbs are on even when I turn on the headlights in the upper assembly.

 

Here's a picture of all the lights on the front of the 2003 Silverado.

https://charm.li/Chevy%20Truck/2003/...Front%20Lamps/

 

Ok thanks
then i have a follow up question! So the bulb i was wondering about is the daytime running lamp. Is it on all the time when the key switch is on? And if so does it have a seperate fuse location? Thanks

 

Everything you want to know about the Daytime running lamps is here. I suggest you bookmark the charm.li site as it has the full service manual for your truck freely available.

https://charm.li/Chevy%20Truck/2003/...unning%20Lamp/

Based on what it says about the description and operation, I was wrong. It only runs when the switch is set to AUTO, the ambient light sensor on the dash sees that it is daylight, and you are not in park, and the key is in the RUN position.