I read this FAQ and tried this first but still have the same problem

OMG The battery and brake light came on at the same time
ALT fuse has blown. It is located under the hood in the fuse box near the battery. It can alos mean the voltage has dropped under 10v. In most cases this means your Alternator is dead/shorted out. Replace the fuse when you replace the alternator.

My alternator and battery are fine. the fuse is fine. I had a mechanic check it out. anybody have any other ideas
thanks

 

Your alternator isn't fine, or the belt might be slipping. Those are both symptoms of a bad charging system for either of the reasons I just outlined.

1000000% guaranteed it's one of these two things.

 

ya its the alternator...it will show the correct reading after charging but it stays defective and will react back.