What is wrong with my 2003 Kia Optima?

It looks like you probably have a bad alternator. If it the battery is only showing 10.5 volts with the car running then something is definitely wrong and it is most likely the alternator. It should show 13.5-14.5 volts with the car running. You should have the battery checked as well. Sometimes when the alternator goes bad it takes the battery with it.