what will make the ac belt brake on 2001 BMW 330i

replace a belt a month one started tiring up...

Asked by for the 2001 BMW 330i
Sounds like you might have a damaged pulley or one of the bearings on the accessory pulleys might be worn out. Check for wobbling in the pulleys while the engine is running. Obviously, it could be other things but that is the first place to check/start.