battery or alternator: Please help

[mptoledo]

I have searched and read all the results on the subject. I just need a little more input.

Went to start my car after the winter sit. Got a new battery as my 7 year old one wouldn't start the car. It is 50ish outdoors. I installed the brand new batter from wallyworld. It is their best gold series. Had some trouble starting it and got an arc when connecting the cables.


2001 boxster "s" 62k miles. Ran perfect before winter.
1.) Battery light stays on
2.) stereo won't turn on(aftermarket jvc).
3.) oil check thing doesn't work, it just blinks
4.) Car stops the second you take off the negative terminal.
5.) Checked all fuses and replaced abs/asr/psm control unit as it had blown

I ran the car around the block for a couple miles gently but spirited once it warmed up. Every thing seemed as usual and no other issues, except the above.

I think I blew my alternator out but is there another way to check or does someone else have an idea?