[T2] Alternator charging?

[Richard Jack]

My light on the dash comes on with key on, then off when engine is running.  So I thought all was fine.  

The full story is:

I put a new battery on three to four weeks ago and all has been great since then.(thought battery wasn't good cause bus wouldn't start one morning. It was a old battery, so I replaced it.)

Everything has been fine.  Drive it daily to work with lights on in the mornings.  Figured if the alternator wasn't charging the battery wouldn't have lasted a day or two.  Then one day after work it turned over slightly slower than normal.  Drove home fine, then wouldn't turn over the next morning. (Which is exactly what happened the first time)

I thought something must be drawing power all the time.  Thought it is my stereo, so I've unplugged it.  Charged the battery and it's started fine.  

Just not sure if the alternator is charging fully, sometimes, or what.  

Ideas?


Thanks!  
Richard 
Lubbock Texas