1994 Cinquecentro (899cc) - I've had 3 fan belts break in the last couple of months. The car is rarely used, so this equates to a broken fan belt per 20 miles or so. What is going on?
Two belts have been replaced by a professional mechanic and the last one by myself. We can see nothing wrong. The water pump is not seized, the alternator is not seized - both spin freely. Everything runs OK, you can stand and watch the engine running and there seems to be no problem. The belt is not over-tightened.
Yet each new fan belt quickly breaks. The fan belts were "generic" - the last one came from Halfords.
Does anybody have any ideas?

check the pullies are smooth and have n little burrs also check the tension bearing is ok also check that the cover is not catching it also does it look like a clear cut or is it a fraid snap

i may be wrong but to me it sounds like they are being fitted too tight.

On the 899 the fan belt drives the water pump as well. So beware. check and see the pump is spinning freely.

Ming

i'd check the cooling sytem for blockages, it might all spin nicely when spun by hand - but be causing trouble once the revs/pressure are up

To answer all the replies to my question:
- the fan belt breaks are not clean. There has obviously been a lot of stess before the break. The broken ends are frayed.
- the pulleys are not damaged, the grooves are clean
- the fan belts were not over-tight
- the water pump does spin freely

The only idea I have is that either the water pump or the alternator sieze or become heavy to turn at high revs or when the engine is hot. It can't be the alternator because if it stopped turning before the belt broke, then the warning light would come on (it only comes on AFTER the belt has broken). Why would a water pump spin freely when cold, but sieze when hot?

just thinking out loud but if it was the water pump siezing would the teeth on the belt before the snap be damaged too apart from that i am out of ideas its abit beyond me as i have never heard of a prob like this before

Engine mount/s not good and causing belt to to touch something on acceleration/deceleration?
Alternator pulley not in alignment?

how rarely is this car being used?