[kglowacky]

update . I removed the heater box today and sure enough the vacuum connection for the all black line goes into the top of the box and connects to the same actuator as the yellow line. This actuator has two vacuum connections, one on the inside of the box which has a short red runner hose to the outside of the box (which is the one that rotted away on my box and then the solid black hose connects to it on the top outside of the box) and the yellow connects on the back of the box on the outside. All put back together and moving on to the next challenge.