Joe, That is true...but if the vacum line to the water valve itself is the only culprit as Nick refered to...then it would always be hot air blowing. Even though all the vents are by passed, and it passes cold air trhough the vents, hot/warm air will always be coming through the defoger vents for the windshield. I am not sure if the Delorean is set up the same way, but three cars that I have fixed had a broken/disconnected vacum line to the water valve and the heat always came through the defrost vents even when the heat/AC was off! It was allot noticable as you were driving, standing still you would not feel it blow at all. What you are describing is if something is wrong with the vacum lines in the car causing that bypass door to stay in one position...or the door is stuck in the AC mode. I hear a vacum test coming on! :-) Steve --- In dmcnews@xxxx, "DMC Joe" <dmcjoe@xxxx> wrote: > Not so!, > > During hot weather when the AC is in use the temperature control is usually > kept in the maximum cold position which closes the heater core > re-circulating door. When this door is closed air entering the lower plenum > chamber bypasses the heater core, therefore only unheated air will enter the > cabin. > > In other words air conditioned cold air will still flow through the AC vents > into the cabin even if the hot water valve is wide open. > > DMC Joe > > If that were the case, then he would always have heat since when > > there is vacum present at the valve it keeps it shut. No vacum opens > > that valve. > > > > Steve (Some quotes trimmed by the moderator)