On the way home from work this afternoon, a new problem got thrown into the mix. I stopped at a local parts store to get a new starter motor and when I came back out, the truck started even rougher than it has been starting the last two days. I started it up and headed for home...

Right in front of my house, the battery, O2, oil, and brake lights came on. I pulled into the garage and shut it off quickly. After I got out and inspected it, I found that the alternator had come loose of its moorings and there was nearly no tension on the belt that rides over the crank pulley. I loosened the bolt fully, pushed the housing as far to the driver's side as it would go, and cranked it back down. I hoped somehow that the noise I've been hearing would magically go away and I wouldn't need to pay the $100 for a new starter, but the godawful grinding noise was still there, of course.

At any rate, it still sounds awful, but now the idiot lights are off. I'm driving it as little as possible until Friday when I can swap the starter out.

Again, does this still sound like the starter? Any tips, tricks, hints, or secrets for when I do this job? This'll be the first time I've ever done a starter, so any help would be appreciated.

EDIT: edited post for clarity. Sorry about the confusion.