Serpentine Belt keeps snapping!

[Andeo1996]

Hey everyone! I'm having a bit of an issue with my 2000 Mazda Protege (1.6 Liter)
My engine has two serpentine belts, one that runs from the crank pulley to the water pump and alternator, and another that runs the same crank pulley to the AC and Power Steering.
Of these two, the one that runs the Alternator and Water pump keeps melting and snapping off!
At first I thought it was the water pump, because it had some resistance when turning, so I replaced it. This didn't solve the problem, and the belt still snapped off.
After this I disconnected the belt that ran the AC and Power Steering.
I than assumed that it must be my alternator, and after replacing that also, the belt still snapped.
I than went under the engine and looked at my crank pulley/harmonic balancer, and noticed that there was a slight wobble, so I again assumed that was the problem, and went ahead and replaced that as well.
And, just like before, the belt still snapped off.
At the moment I'm kind at a stand still, not knowing why the belt keeps breaking. I checked the belts for any misalignments, and didn't notice any.
Any ideas on what might be the problem would be awesome!
Thanks

 

[luigisho]

When I had an issue with belts breaking my factory 2 piece harmonic balancer was coming apart. I have seen frozen pulleys cause enough friction to ruin belts. So you are on the right path. either an accessory is not turning correctly or an idler or tensioner might be stuck or misaligned or damaged. When you say you replaced it is that the entire water pump alt or just the pulley on them? if something is damaged internally that can effect how the shaft and pulley spin.

 

[SHOdded]

Mazda Protege. Hmm.

Are you using OEM belts, or ...?

 

[Magna]

Only 3 things I can think of is.
1 Seized idler, but then you would smell burning rubber or squealing
2 Bad belts
3 A burr on one of the pulleys after installing new belts

 

[Hvyleaf]

I didn't read the whole thing, maybe the pulley alignment is off. ? Seized pulley? Slightly undersized belt? ?

 

[rubydist]

Does that belt have an idler pulley or two? I have only seen the thing you describe happen with a bad bearing, in your case it seems to be fine part of the time, but will randomly seize up during use destroying the belt. My bet will be on a bad idler bearing that seizes up on occasion.