It can be connection wires, bulbs or fuses.
every vehicle must have brake lights to indicate that the vehicle is stopping. with no brake lights the vehicle can cause a rear end collision.
A malfunctioning brake light relay switch will cause your 1993 Toyota Corolla brake lights to stay on all the time. The brake light relay switch is located beneath the drivers side dashboard.
Do you mean What does it mean when the brake and battery lights come on in when it is already started? Check your alternator may be its not working well it cause the battery sign comes out.
Alternator has/is going bad.
fuse, bulbs
brake light switch would be most common cause
witch lights
BAD BRAKE LIGHT SWITCH AT TOP OF BRAKE PEDAL
The BOO (Brake On/Off) Switch may need to be replaced. If it is bad, it would cause the brake lights to NOT illuminate when the brake pedal is applied.
Possible ground issue at the taillights.
Blown fuse or defective brake light switch.
Most likely a fuse.