I noticed today that my left brake light is out but my night drive lights still work so idk if it's a fuse or relay and which one cuz I ...

I noticed today that my left brake light is out but my night drive lights still work so idk if it's a fuse or relay and which one cuz I don't own a owners manual. And about a week ago I noticed my inside cargo lights and reverse lights went out... Any suggestions I check all the bulbs and they are fine and some fuses but don't know witch one to change. Has anyone had these problems...?

The manual's here: 2003 Silverado Manual

Did you check the sockets with a test light or volt meter?

No not yet but if worst comes to worst is that an expensive repair?

Electrical is more about time than money. If you can learn to do it yourself it's the cheapest thing (unless it's a problem with a control module). If you are looking to pay someone to chase down electrons, the sky's the limit.

Autozone has on line repair manuals which include wiring diagrams that you can view free if you register with them. You can pick up a test light for a few bucks at places like Harbor Freight as well as multi meters.

DC electronics is first semester stuff. Pretty easy to pick up, but there's always more to learn.