I have a 1995 Jeep Grand Cherokee, 78000 miles. I had my ac freeze up this summer, so I've just had that and its related belts replaced.

This week it has gotten colder in my area and when I start up the jeep it makes a sort of 'wip-wip-wip-wip' sound from the belt assembly for 2 or 3 minutes after start up.

Other wise everything is working fine and this only happens when I start it in the morning. I start it at lest 3 other times a day and it has always been fine. Any ideas?

Belt tension, might try either replacing the tensioner, or tightening the belt a little bit more.