Chosen Solution

The light goes out after the 5 minutes driving?

The “Battery Light” really is telling you the electic power to run the auto is coming from the battery and not the alternator. Check that.

crowder451, if your getting 15+ volts when warm, that is pretty high and regulator may be faulty, check the attached link for good info. and trouble shooting charging system. http://www.aa1car.com/library/charging_c