The Car spent all of its life in Texas until now so this feature was probably rarely used. There is no heat entering the passenger compartment, defrost pulls all the way out, but only blows cold air. The far right pull knob does not come out very far, but I'm having trouble trying to figure out what/where it is actually pulling at the other end to help it along. I see no Fluid Control Valve under the hood, just hoses going into the firewall.:confused: Drawing in the Manual is hard to distinguish what should be going on, just basic routing of the cables. Description of the system operation is v