My belt keeps breaking. I detect a burning smell right before it breaks. I think it might be because my power steering pump pulley is not turning. Otherwise, it starts right up and sounds fine.
It appears that the power steering pulley has seized as a result of a failed power steering pump on your Ford Windstar. The burning smell is due to the belt rubbing against the non-moving pulley which creates heat and friction. This eventually leads to a broken serpentine belt. I recommend enlisting the assistance of a certified mechanic to come by and verify the condition of your power steering pump. They will also be able to assist you with replacing the power steering pump as well as installing a new pulley.