2004 Chevrolet SSR - Many electrical issues

While driving and about 1 1/2 hours from home, suddenly the ABS, traction, seat belt, and battery lights all came on, the gauges stopped working correctly, the air conditioner started blowing hot air, and now the back bed cover will not open. However the truck still ran smoothly all the way home, and has no problem starting. We disconnected the battery, but everything still happens when we start the truck. What is happening?

The BCM may be failing.

Tester

There may be trouble within the alternator causing this issue. A simple way to find out is to disconnect the connector going to the back side of the alternator, not the main output lead. That wire is HOT at all times to the battery so disconnect the negative lead of the battery before ever working on that lead. After you disconnect the smaller wires going the alternator start the engine and see if things settle down. The warning lights are tied into the alternator circuit for testing purposes.

Does battery measure 12.6 v b4 first start of day and 13.5-15.5v immediately after starting engine? Thats the first test.

Thank you for your assistance.

We will look into that, thank you. Battery is only about 3 months old, but will have tested.