Electrical Problem with my 99 SC-1

I've had a 1999 SC-1 Standard for about seven months. Recently I started having a weird thing happen - It doesn't happen all the time but is increasingly more frequent. When I press on the brake, it seems to disrupt the entire electrical system. The interior and exterior lights blink, the ABS, Low Fuel and Brake lights come on and all the needles drop to zero (Speedometer, RPM, Gas). This only lasts for a second, then everything goes back to normal. Usually. Sometimes the ABS and brake lights stay on until I turn the car off and restart it. Then it will be fine until I need to press firmly on the brake again. If I make the car slow extremely gradually, that doesn't usually happen although the car seems to experience a more minor, momentary power drain. I would really appreciate any ideas or suggestions. I've taken it for a diagnostic once and they didn't find anything.