Make sure your alternator is seated properly. Any gaps will set the pulley offline.
I don't know if its just me but installing the ac belt is harder than replacing the alt, waterpump, ect. Even with the special tool. Good thing I don't have to do it again, drive it till it snap then I will change it.
The dependable- 2011 Acura MDX Advanced
The garage decorator- 2008 BMW 550i M Carbon Black
2013 Triumph Daytona 675R