Symptoms of a malfunctioning alternator would include:
*battery running dead
*hard starting (slow cranking)
* Battery or charge light illuminated while the engine is running
*noise from the alternator when it is turning
*Alternator becoming too hot to touch comfortably when it is running.
ANy or all of these things could indicate a possible alternator problem. Most auto parts stores will test your alternator for free if you take it in to them.
Hope this is helpful and answers your question; if so, please click my "accept" button! Thanks!