Brake light won't turn on, already changed the bulb but it still doesn't work

It could be, but before you go around swapping fuses and wiring harnesses, try this first: check if the metal contact inside the light socket is actually making contact, sometimes it gets loose or corroded and then the new bulb just won't light up. If the contact's okay, then it's worth checking the brake fuse (which is usually in the fuse box under the steering wheel or in the engine bay) and see if it blew, because if everything's burning out fast it might be an electrical problem in the wiring harness itself, then you're gonna need a multimeter or take it to an electrician to track down the fault.