No power to radio, windows, wipers

I have a 1999 dodge caravan sport and it just recently started to have a problem. When I crack the van up it sounds like a small pop sound under the dash and I have no power to the wipers, windows, and radio, and the air then switches to the defrost automatically. However, when I turn the van engine off the accessories then come back to life, but they go back out again when I start the motor.