[john walker's workshop]

they seize when overheated. don't use it anymore until you check for a full charge and sufficient compressor oil unless you want to buy a new compressor. may be something else, but best to have it checked out. maybe a condenser fan isn't working. for instance, if you run the A/C with the engine lid open, which cuts off the airflow to the rear condenser, the compressor will start binding, causing the belt to squeel.