2000 Hyundai Sonata Alternator problem?

[anything i want]

I need help with my car, i really don't know what the hell is goin on...i see on the dash the little battery symbol and the brake light on, i'm guessing is the alternator since i was driving the car and it slowly DIE on my, first the radio, the light, then the car. So i took out the alternator to have test and the say that it's not the alternator, so what can it be???, i really don't have money to be guessing on different things...is there a way on buying a new alternator and "try" to see if that's the problem?, if i still have the prolem can i return the new alternator???
HELP PLEASE!!!

 

[howardtuckwell]

why in the -----did you buy one of those for/ should have done some homework or used common sense, sell the thing now b4 u loose more money/ check the value now at a garage.... the worst car 4 depreciation...