Rod2190

Brake lights work with headlights or parking lights off but not when on, also if headlight switch is turned on and I press the brake pedal with no key in ignition all dash lights and gauges come on like the ignition has been turned on with key but only when headlight switch is on... Any one familiar with this issue maybe a bad module or something I really want to fix on my own, I'm a college student can't really afford to take to a shop... Thank u any info is much appreciated.