Alternator?

ok, now I am separated from my stang by about 250 miles. The reason? Well my stang is back at my parents house because for some reason the alternator stopped charging my battery which happened when I was driving on the highway when most of my accesories shut off one by one. Then right as I turned off onto an offramp( to see what was wrong) my car went dead and my powersteering shut off so i couldnt steer( only thing I had was the brakes). now it was rainning that day and my dad thinks that either water got into it or that because it was old it finaly died. I still think that my Pertronix 12v coil was too much and drained the battery. I would like opinions.

Thanks for the info. I was curious to find that both wires leading from the alternator were covered( not a pro job) with electrical tape. And the morning of the day I left, the battery was almost dead for some reason because upon starting, it had barely any energy to crank over. My dad was already going to have a guy test it and replace if neccessary.

I have a brand new alstate battery. Its bigger than the original 1