When to get a new Alternator

[billdo]

Should I wait until the red light comes on, or should I be proactive. I just had a scare with the battery. I thought it was the alternator, then the starter, and finally figured out it was simply the battery, it was 6 six years old.

So now I am worried about the alternator. I have an 2003 3.0i. I just unlocked the dash menu to check voltage. I got 12.0v on the new battery, probably is higher than that. And I got 13.6v with the car running at 2,000 rpm. Shouldn't it be higher than that? Should I be ready for the alternator to fail?

PS, hope your starter never gives out. What a PITA it is to change that thing.