There are several things that can make your headlights not work. First the might have blown a fuse, or maybe the bulbs burned out, or the battery might have died.
Bad ground on the brake lite circuit.
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.
A bad ground wire will cause dim headlights, or will cause lights not to work.
If by "dim headlights" you mean low-beams... the bulbs are bad and must be replaced.
Most likely a fuse.
bad light switch.
my headlights work but my taillights and dash light dont work whats wrong
Headlights don't work on 90 tempo L, fuses are all good.Filements are also all good in headlights. New headlight also does not work...
They are either the wrong bulbs or one of the filaments is burned out. The bulbs should have two filaments. One is illuminated when the lights are on. The other is brighter when the brakes are used.
Faulty ground to the dash.
If it's an electronic (analog) speedometer needle, you probably have a problem with the dasboard grounding.
The switch is broken. You need to replace it.