I just finished the resto of my 70 RR ac heater box. Hooked the hoses up tonight. After all the hoses are hooked up to the acuators you should have two left. They run through a gromet in the firewall one is short and hooks up just outside the gromet, the other is very long maybe yours was cut. It comes out the firewall then runs with the harness over to the drivers side, then down to the front through the plastic straps and then connects to a can under the battery tray. I beleive that would be your vacum source.