Belt All messed up

Well my Serp keeps popping off of the ac compresser.I put a new belt made sure all the bolts are tight.Does not happen when floored it has happened to me both times when iam just started to go maybe at like 5-20mph.It snapped the other day and got wrapped up in my ac wires so i had to run new ac wires.Well it did it today and got hot that how i know it popped off.Plus I just put a new pully on there and its on there right.What can i try to do next.

Scoot

Check the ac compressor to make sure it is rotating freely. It could be locked up. Also check the belt tensioner. If they are week or stuck they will allow the belt to fly off when under stress. Finally, check the crank pulley to make sure it is tight and not bent in any way. Alignment is critical so any of these can cause issues.

Well i found the problem there was a very small pebble stuck so 1 of the pullys could not move and was popping the belt thx gtp.

Scoot