GM-GMC: GMC pickup, gmc pickup, gm vehicles

Question
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Followup To
Question -
I have a 93 gmc c1500. I just recently changed the serpentine belt. Directly after- I noticed that my truck was driving differently- It seemed to be straining and it felt like there was a lot of pull on the engine when I accelerate. I took it back to the shop that changed it and he told me "not to worry about it-it would probably just loosen up over time".
Well, 2 weeks later my alternator died. I was told the bearings were bad.
Are the two related?
think my tensioner may be bad- I just replaced my alternator and am afraid to drive it until I know I'm not going to damage this one as well.
I have put in 2 refurbished alternators within the last year and a half- (this time I bought a new one). Can a bad battery kill an alternator?

Also-completely unrelated- For the last 2 years my truck has made a clunking noise for 45 seconds every time I turn on/off the car. The noise comes directly from under the passenger side dashboard and goes on if I turn the heat or air on. The heat and air still work- but I would love it if I could solve fix this.
Thank you so much for your time.
D
Answer -
The new seperntine belt could have put additional strain (from higher tension) on a marginal set of alternator bearings.  Result:  Alternator failure.

The tensioner will usually get noisy or jump if its bearing is going bad.  If the belt is removed, the tensioner should spin freely and without noise.

A bad battery can cause an alternator to run at higher output than normal.  It could shorten the life of the alternator.  Newer alternators (after 1986 in GM vehicles), however, will not charge a battery if  its voltage is too low.

Your clunk is the air door on your heater and air conditioning system.  Some cushioning foam or rubber has likely come loose or fallen off of it.  Tearing the dashboard apart is not worth it unless it quits functioning.

When we were trying to move the tensioner to pull the belt off it was really hard to move. I've watched mechanics do this with ease about a year ago- but this was much harder to move than what I watched. Can it be there is something jammed into the tensioner? It didn't exactly move"freely" when the belt was out.?

Answer
There is usually a 1/2" square hole on the tensioner for a ratchet or breaker bar to move the tensioner (the mechanics likely had a special tool for this purpose).  It is supposed to be hard to move because there is a large spring inside of it.

The movement I was talking about was the tensioner pulley itself.  It should rotate freely and with no noise without the belt on it.