I'm having a problem with my 96 GT. I started it yesterday and when I turn on the park lights the engine runs rough and then stalls. Same thing happens when I put my foot on the brake pedal. The signal lights blink fast and my break lights go dim. I cleaned all the grounds I could find and that didn't work. The only thing that seems to work is when I leave the battery disconnected for about an hour and then everything works fine for a bit. Any idea what it could be?