1990 Isuzu Pickup Truck problem. Replaced Alternator and "LOW FUEL", "BATTERY", and "BRAKE" are l

1990 Isuzu Pickup 4x4. Initial symptom was 'dead' battery, which I jumped to get going. Sometime later in the day, the heater/A/C Blower motor suddenly stopped working, and the A/C clutch will not engage. The alternator fried at the same time, so I replaced alternator. Had battery and new alternator verified *GOOD* by two independent diagnostics. The following dashboard warning lamps are illuminated: "BRAKE", "BATTERY" icon, and "LOW FUEL" pump icon. A/C will not engage the clutch on compressor pully when you press the A/C on, nor does the blower motor work. I checked each fuse on both fuse blocks and there is no blown fuse. What could be causing this problem?