warren (07/21/82)
I am considering trying to correct a minor annoyance in my 79 Rabbit. The car has air conditioning, and is designed with the air conditioning and the fresh air/recirculate controls coupled, so that in order to shut off the flow of outside air, you must move the temperature control to the coldest setting. Thus you have the following options for climate control: Car Closed (no fan, heat, cooling, or fresh air) Maximum air conditioning (Coldest setting, no fresh air, any fan setting) Normal air conditioning (Any temperature, Any fan setting, with fresh air) Ventilate (Any fan setting, No heat or cooling, fresh air). Heat (Any fan setting, Any heating temperature, Fresh air). What I would like to do is to install an independent switch controlling the fresh air/recirculate function, to allow both heating and cooling at any temperature setting without introducing outside air. This will save significantly on air conditioning on hot, humid days, and would most likely allow better temperature control while the car is warming up in the winter. I have the "standard" VW service manual, but it has little to say about the ventilation control system, and less to say about the modifications for air conditioned cars. I am not even quite sure how to access the controls. My observations/guesses about the system are: The controls seem to be removable by prying out the panel in which they are mounted from the dashboard and the ventilation control works from a pneumatic control powered by engine vaccuum. Does anyone out there have more info on this system or on the ease of making such a modification? (Before I get a flood of comments about poorly designed cars, let me point out two very desirable and very unusual features of the Rabbit ventilation system: Any temperature can be delivered to any outlet, rather than limited combinations. I have found this useful for doing things like cooling perishables on the floor by running cooled air through the outlets normally devoted to the heater, and for quickly thawing my hands by delivering heated air through the dashboard vents. The airconditioner also controls temperature by cycling the compressor on and off rather than by re-heating cooled air with the heater, as is done in most systems.) Warren Montgomery ihnss!warren