Ac blower replaced, now car stops while idle, battery light flashes and no air

What is your question?

Before replacing the blower, the air conditioner would sputter on and off and would only work at its fullest on the highway. Then it went out completely. My dad changed the blower and it started working. Now the ac has stopped again and the car has stopped twice while idle at a stop light and then the battery light flashes. Is the ac draining my battery? My battery is fairly new so I just don't know. Is it something else like the compressor or clutch? I am dreading the repair costs. Please help in any advice you can offer regarding this issue. thanks