2003 2.0 Zetec

I had my Alternator rebuilt and I reinstalled it last week. All seamed to be working well until a couple days ago and the battery light came back on. I tested it yesterday and its pushing 12.6 volts. Could this new alternator have already gone bad? Is there something else I could look into? I just keep thinking I might have connected something wrong or forgot to connect something when installing it maybe? Also, the ground wire that connects to the body by the strut, where does the other end connect? I connected it to a bracket on the engine where I "think" it came from. Last night I disconneted that wire just to test it and it still started and ran fine.
Any ideas would be greatly appreciated. I just REALLY dont want to take this Damn alternator out again.

Thanks, Jon

 

If you had the alt rebuilt by a local shop you might stop by and ask them to check if their rebuild job is working correctly. Most times they don't mind checking their work.