Battery is charged but on 1998 Jeep Grand Cherokee

Jeep makes a squinking sound when I turn the defrost on then ck Battery light comes on, after I turn defrost off and shut down engine everything starts back just fine

1 answer 1 comment
Depending on the mileage of your vehicle, you may have a generator that is starting to fail intermittently. i also suggest you have your battery tested and make sure your battery cables are clean and secure.
The battery cables are clean and secure, plus its a brand new one, I thought it may have something to do with the belt on the ac pump since it only happens when I put it on defrost?