No power to some fuses (Htr, A/C, PwrWindows) all of a sudden???

My 95, 4dr, 4x4 Jimmy worked normally in morning, but after parked for a few hours, the pwr windows & blower motor stopped working. There is no elec power getting to these fuses and two others - brake and another I don't recognize. Also, the air bag and brake lights are also lit when the vehicle is running. How does power get from the engine compartment to the fuses and what might be interrupting these paths? The vehicle runs normally, but has lost power to these components. Help, please.