2002 Pontiac Grand Am with lights draining battery w/i two minutes of

[CatGirlKelly]

turning engine off - WHY? I have a 2002 Pontiac Grand Am (and I love it!) However, I discovered that for some reason keeping the headlights on with the engine off even for just a couple minutes will drain the battery to the point where I can still start the car, but the radio resets like the battery was completely dead. I had a mechanic check the battery and it's fine. If I turn off the engine and keep the radio on, even for over 15 minutes, the battery is still fine. It's just the lights that cause the problem. What could it be?
Thanks

 

[JFyfe]

Sounds like a short - Do the headlights dim or brighten under load?

 

[motorhead'n'black]

Do the headlights dim or brighten under load?

Or when you 'rev-up' the engine?