Need help...Odd electrical problems '00 Alero

Hoping someone can tell me what's wrong with my car.........started today. I have a 2000 Alero with approximately 205,000 miles. Been a great car until today. Out of the blue, the Anti-Lock, Trac Off, and Air Bag light came on when I started my car. Then, when the car shifted it would "jump" into gear and idled high and wouldn't go into a lower gear. Also, the air conditioner would blow but not cold air. Then, all of a sudden, it would shift fine, air conditioner was cold, and the odd lights would go away. Then, few minutes later, it would act up again. On my way home, as I was putting on brakes to slow down, the car stayed idled really high even though the car was slowing down. Lights had come back on and air conditioner off again. I've tried disconnecting the battery cables and cleaning the posts, also to see if it would "reset" something. It didn't work. Has anyone else had this problem? I'm at a loss right now. Any advice is appreciated.

:banghead:

Welcome to AF !

I would test the battery should be at least 12.4vlts with the car off, and around 14+ vlts with it running.
I'd also inspect the wires to the MAF sensor and check for vacuum leaks.

If thats all ok get it scanned with an ABS capable scan tool.

Welcome to AF !

I would test the battery should be at least 12.4vlts with the car off, and around 14+ vlts with it running.
.

Yup.

Voltage problem. Alternator, or battery. TEST; don't buy.