I had the compressor replaced 1 year ago and for the last 3 months the air conditioning will blow cold intermittently. There is no rhyme or reason how to get it to blow cold. I used to have a Ford Crown Vic that had a blend door problem and it requires removing the dashboard to get to it. Instead I installed a brass ball valve on one of the heater hoses under the hood going into the fire wall and would turn the valve off when wanting air conditioning. However it only blew arctic air ice cold only using that method, no temperature adjustment. I digress. Is it possible the problem is the blend door? I assume these vehicles utilize that technology in the AC system. Any ideas would be appreciated.