Paul, That vacuum hose connects to the water valve for the heater core for the A/C control system. Refer to the parts manual....location in manual...7-1-3 fig 2. This valve is controlled by vacuum supplied by the mode switch inside the passenger compartment. To located the water valve, there is a water line coming from behind the drivers side cylinder head that leads to the passenger side, the water valve is "in-line" on that hose. You should feel a vacuum valve that the vacuum hose connects to. The rubber line hooks up to that. Hope that helps some. Later, Nick 1852 15914 <A HREF="http://members.aol.com/njp548">http://members.aol.com/njp548</A> Happy Holidays!