2007 CHEVROLET EXPRESS 2500 Electrical System Problems

I WAS THE SOLE OCCUPANT. CONCERNING THE INFORMATION ABOVE THE DATE IS ACCURATE WITHIN ABOUT A WEEK AND MAY BE DETERMINED EXACTLY. MILEAGE IS CORRECT WITHIN A THOUSAND MILES. MY INJURIES WERE NOT MAJOR AND I DECLINED TREATMENT SPECIFICALLY BECAUSE I NEEDED TO DEAL WITH THE WRECKER AND SUCH. END OF PREAMBLE I WAS LEAVING THE GARAGE AT THE CONDO WHERE I LIVE. THERE IS A STEEP INITIAL GRADE ENDING IN A 90 DEG. LEFT FOLLOWED BY A MORE MODEST DECLINE ENDING AT A STREET WITH TRAFFIC. BECAUSE THE RAMP IS NARROW AND EVERYTHING DISAPPEARS FROM THE DRIVER'S VIEW, I WAS TAPPING THE BRAKES AND CHECKING THE POSITION OF THE BACK WHEELS, WHEN THE BRAKE PEDAL CEASED TO FUNCTION. I TRIED IT AT LEAST TWICE AND THEN GOT BACK TO STEERING. AT THE TIME MY ASSUMPTION WAS THAT THE ENGINE HAD STALLED, EVEN THOUGH THAT HAS NEVER OCCURRED PREVIOUSLY. I...