01 T&C belt squeals sometimes at startup; compressor clu

Our 2001 Town and Country's belt has been squealing at startup periodically. It seems to be mostly at startup when the van is cold. I've also got it to quit by pushing the A/C button to off. Everything seems to work fine after the squeal stops. The squeal usually is 3 to 5 seconds, but it did do it once for 10 to 15 seconds.

Is the compressor going bad? Or does the system need oil? Do A/C clutches lock up?

The van has just turned 100,000 miles and the compressor was replaced at 65 or 70k by the dealer.

Thanks