Bad ground on the brake lite circuit.
first check to make sure #1 you have the proper bulbs #2 the bulb is in the socket correctly.either of these could cause the circuit to back feed
check the fuse on the fuse box, the bulbs,or the connections.
which fuse would cause your brakelights,blinkers,dashliht not to work
My '88 Prelude Si 4WS had a short in the steering column. My "guys" pulled wires to a toggle switch that they free-placed in the coin tray. It gets hot . . . But, the running lights/brake lights work independently of the headlights!
A bad ground wire will cause dim headlights, or will cause lights not to work.
WHAT ARE YOU DUMB REPALCE YOUR LIGHT BULBS STUPID! Not stupid replaced circuit boards checked fuses ran test light . When headlights are on no brake light or taillights and have all new bulbs stupid. Turn headlights off brake lights work, so figure that out smart man
You could ride into one and smash it on purpose If you interrupted the flow of electricity to the lights they would not work. Ie, broken bulb, broken wire, blown fuse.
bad light switch.
There are several things that can cause your 2003 Kia headlights not to work. The most common cause is a loose or corroded ground wire.
You probably won't have dash lights either. The problem will probably be at the light switch. If you take out the switch, there will be a burnt wire, and the switch will have to be replaced, along with a pigtail for the burnt wire.
Faulty ground to the dash.
If it's an electronic (analog) speedometer needle, you probably have a problem with the dasboard grounding.