Fan belt snapping

We'll I'm on my 5th belt in 3month or so and it's really starting to annoy me as I can't really rely on the jimny incase it brakes some of the belts are clean snaps and others are just shredded .i don't understand why it's happening as everything is turning Freely . On Friday I fitted a new belt and it snapd before I got a mile from home so I went home and fitted a new belt now it snapd agane last night it was a clean snap and now it's lying in a village miles from home seriously considering selling it for spares or repair had enough now

Staring to worry now that uve got the same but slightly worse problem. I was really hopin I had put mine on too tight. All try look into it further and keep you posted.

Something is seizing or out of alignment as belts don't just break or snap especially new ones.
I know it's difficult to check when hot but is everything free immediately after it breaks?
I'm thinking something is locking up when hot?
The shredding would also point to a partial lock up.
Thinking logically obviously the crank is ok so that leaves the other pulleys/idler?
If I remember correctly Jimnys used to have a problem with the crank pulley cush drive breaking up?
Is everything in alignment with no damage or wear to the pulleys?
Is the water level ok? Or is it overheating before it snaps?
Can you twist the belt about 45-90 degrees just using your finger and thumb after tensioning it up?
These are just general questions and not about the Jimny as I'm not sure what the belt drives on the early Jimny?
Alternator bearings??

Yeah everything turns Freeley with no belt on but once I fit belt it dosnt turn ?? Yeah the temp rises and battery light comes on that's when I notice somthings wrong

Could just a small burr on one of the drive pulleys. Would only need to be small to cut through the belt at high revs.

try looping the belt round each pulley individually and pull on the belt by hand with some force and at the same time try to rotate it to see if something is jamming the pulley(s) under tension.
If you do each pulley in turn it should hopefully pinpoint if any single pulley or component has failed??