if you have a local garage near you have take your car to them and have them check the amperage on your alternator. They'll probably stick a VAT-40 or something near that on there and it will them the amperage. I know autozone doesn't have a vat-40.......well maybe they do but i seriouosly doubt any of them are smart enough to use it the correct way. Just try a local auto shop, i'm sure someone can clamp an amperage clamp on the wire and find out the charging state.