This problem exist with a EATC system that is not blowing hot air even thought the blower function is working on automatic or manual. The a/c clutch is on at all selection while the temperature is evented at the maxium heat seting.The a/c relay is ok.I have done a complete service on the engine side of the system.I have concluded it is the blend door or the EATC module.Can anyone verifie or help me on my diagnoisis?