[Mgs] alternator question

[1971-red-mgb]

I have a question about the alternator in my 71 "B", it is raining pretty hard
in this neck of the woods and as I was waiting at a red light waiting for the
light to change to green, the engine was just purring away then suddenly the
alternator light came on to a bright amber on the dash,  then the engine died,
I turned the key off and on again and the car started right up, a few times
after that the alternator came on momentarily and the car acted as if it
wanted to die, I accelerated and the car ran fine, any ideas and suggestions,
perhaps the alternator going kaput?