If parking/dash lights work check bulbs double filamented smaller filament is for tail lights If parking/dash lights do not work check fuse
Check the fuses.
Probably a fuse that has expired, change it.
The GMC dash tail and parking lights are on a different fuse from the brake lights. Check the fuses for a possible blown fuse.
To locate the dash lights fuse on a 1999 Honda Accord to find out if it is causing the dash lights do not work when you have the parking lights on after installing an after-market radio, check the owner's manual. You can also find a fuse diagram at most auto part stores.
The Switch may be bad. Check the bulbs for the parking lights. Check the fuses / relays for the parking lights.
They're on a different circuit. The parking and dash lights go through the headlight switch. It could be the switch, a bad wire/connector or a burned fuse.
Check fuse for tail/parking/dash lights
u need to replace light switch
If you have multiple lights that do not work it's probably caused by an electrical problem such as one or more fuses blown or a faulty connection somewhere.
If your parking lights are on and your left brake light doesn't work, the brake may have burnt out. You might also have a wiring problem.