Engine Stalled While Charging Ac And Won't Restart

I was recharging the trucks AC system and it was going fine. I had charged 2 pounds of the 3 pounds total, when I changed the selector switch from Normal to Maximum. When I did this, the fan started to increase it's speed and air volume and then suddenly the engine stalled and will not re-start. There's no fuel being sent up to the carb. and I changed the fuel pump, thinking it may have gone bad. The new pump didn't help. There was also no gas being sent up by the old fuel pump. Is this an electrical problem. A short or something? Is there a fusible link anywhere in this vehicle's wiring that may have burnt or broke? Also, the dome light switch, mounted on the driver's door jam isn't working properly. When the door is closed, I can read 12 volts at the connector, 0 volts when the door is open. It's working just the oposite way. This is an '80 GMC 1/2-ton PU, 305, V8, automatic. Thanks for any tips!