If Car headlights get dim and horn goes mute after few kilometer and battery discharges but it works fine without head lights what is the problem?

If Car headlights get dim and horn goes mute after few kilometer and battery discharges but it works fine without head lights what is the problem?
It sounds like a direct short in the headlight circuit . Check for shorted wiring to the headlights and tail lights . Could also be headlight and or dimmer switch .