I have a 2005 exp. New alternator. The battery drains unless i take off negative terminal on battery. WHY?

There is a power draw from battery,or battery may have weak cell,none the less,this can be checked,by checking the amp ,s on the battery why it is off,and if there is a draw,start by pulling fuse,s out of panel,untill you find the draw.

If your battery is draining when the vehicle is off, there is a draw on the battery when the vehicle is off. Check things like glove compartment/storage lights, trunk/rear hatch, hood lights, etc.. If there is an aftermarket stereo installed verify it is wired correctly. If you have a way to test the draw on the battery, you could pull fuses out one at a time until the draw goes away and narrow it down that way.

Found this webpage. Very good info on here for battery basics and how to test for draws: http://randysrepairshop.net/testing-for-battery-drain.html