1988 GMC C2500 died when coming to stop

Thursday, 9/24/09, I pulled up to a stop sign and it died as I pressed the brake pedal. It had not been running long, 5 minutes +/-. It would not restart. The headlights and interior lights worked, but these didn't; blinkers, sounds such as ignition or lights on, radio, power windows, idiot lights. I checked every fuse, all where good. I ended up leaving it right off the road where it died until my husband came roughly 2 hours after the initial shutdown. He is inclined with vehicles and has always done our work. After several turns of the key over a 15 min period still nothing. He couldn't figure out the problem. Then as luck would have it, he sat in the truck and said "start", it did. While it was running he jiggled some wires and fiddled with various things with no result and upon touching the brakes it died again. Then after a few tries it again started and has been fine since. He drove it about 15 miles home and it has been driven twice about 2 miles each way through our small town with plenty of stops. I very rarely have any problems with this truck it has always been dependable. I drive 18 miles to work everyday and I don't want this to happen while I'm alone at 4am on the road. He says he can't figure it out till it happens again and I refuse to drive it. Any suggestions.