Don't get too concerned about the alternator just yet. Pop the hood and check the connection on the top back of the alternator. It may be hard to see as there is a heater hose that routes right over the top of it. Check that wire, because the heater hose itself will actually occasionally knock the wire loose and make the light flicker or stay on, depending on how loose the connection is. This happened on my '95, and when you compare the ten minutes and 3" strip of electrical tape I used to solve the problem to the $250 price tag on a new alternator, what have you got to lose?