You're going to have to be more specific.
You are, in essence, asking the whole world wide web to call your mechanic about your alternator. I don't think anyone is going to call toll free to find out they have no idea what your talking about.
There are plenty of people who know tons about your alternator, what does he need to know?
What is the part number?
How many amps does it put out?
What kind of voltage does it produce?
How much does it weigh?
What color is it?
Where do you buy them?
How do you get it off?
How do you test it?
There could be 17,000 different questions, and most of the answers should be known by a mechanic. Please don't take this the wrong way, I'm trying to help you understand how forums work.
Ask a question, be as specific as possible, and you will get answers from enthusiasts that have similar interests.
1996 Airstream Excella 28'
2007 GMC Duramax 4x4 CCSB