Check your fuses
Check the headlite switch.
May have to be turned off manually Auto sensor bad
Check the brake light switch.
check the fuse. check to see if the wires are damaged under the fender.
Check the fuse, bulbs and actual regulator switch in that order
Check the signal light fuse, the signal light relay, and the signal light switcher.
The switch could be bad. There could be a loose connection on the fuse box, or on the rear of the instrument cluster.
A broken wire or short in the wiring.
There is a circuit board inside each light that usually shorts out. They cost around $30 each. The bulb attaches to the board
Sounds like the brake light switch is defective.Sounds like the brake light switch is defective.
There is a switch for that. It is in the dash illumination brightness control switch.
If you have a 1998 or newer it could be a fuse in the power distribution center under the hood. The whole trailer light system is fused through there.