1996 GMC Sierra sometimes engine cranks over but won't star

Recently my truck has been stalling out or not starting at all. When this happens I loose power to the fuel pump. My idiot lights on the dash don't light up. My turn signals don't work, neither does the seat belt buzzer. But the shift indicater light works as does the emergency flashers and my radio, also my fuel guage fluctuates The pump and sending unit were replaced a year ago. I dropped the tank and checked out the connections at the pump, they seem to be okay. When the problem occurs there is no power back to the pump.I checked the battery connection and they are ok. Could this possibly an ignition switch problem?This is an intermittent problem, It has been starting after awhile, but seems to be getting worse.