Hi,
My 98 Honda Civic had a check engine light on, and the speedometer wasn't working. I took it to my regular mechanic, who replaced the alternator (without notifying me) and said it worked fine for a drive, but as he was bringing it back to the garage the engine light came back on, he smelled something and the fuse was blown.
I haven't driven it except home, but when I drove home the light wasn't on and there's no problem... yet. Online I found a bulletin from Honda saying it could have been "the engine wire harness rubbing on the intake manifold bracket." Now, my question is did I not even need a new alternator?? I lost my job and really couldn't afford the thing anyway, especially not if I didn't even need a new one!
Any thoughts would be appreciated... thanks. I know it's hard to diagnose without seeing the car.

This sounds like an intemittent wiring problem. This could be the problem the Honda bulletin referenced. The quick solution is to insulate the wiring harness from the intake manifold with electrical tape or a similar fix. The alternator probably did not need to be replaced but ask your "regular mechanic" about that situation. He may have good reason for replacing it.