Battery issue

Ok, so I installed my new Powermaster 140 AMP alternator on the old 2.5L S-10, and I rewired my electric fan, since before the electric fan was killing the motor. So I get the truck running and all that happy crap, I pull it out of the garage, and the lights seemed a bit dim, but I pressed on to the end of driveway and into the street....I put it in first gear and got to about past my mail box, and everything went WAY dim, and I did all I could do to get the S-10 back up the driveway and into the garage. I shut her down, and tried to start it up again, and it seemed like there was no juice to start the truck. I put the meter on the battery and its down to like 11V. Could a high amp alternator kill a battery? And my jump pack was dead too, so thats plugged in right now, so I more or less have to wait until I can try to start the pig again. Any ideas?

L8r

Do you have your exciter wire conected? Sounds like your alternators not working I did the same thing recently when I install my engine driven compressor. Triple check all your connections

yeah I checked all the wiring again. I put a meter on the battery and she is reading low. I have to jump it later on and see, but I'm curious if my battery is at the end of its days...if all else fails, I'll swap the alternator back to stock and see if that clears up anything.