The problem is when my headlights are on. The brake lights do not dim when the brake pedal isnt being pressed, they stay fully on the whole time the headlights are on. But when the headlights are off they work fine (they stay off until brake is pressed). So i know it not the switch behind the pedal being stuck.

Does anyone know what the problem would be, and could also fix it, if its not something simple.

thanks...