So I spent some more time tracing wires and testing and jiggling things, and I managed to get the blower motor working. This is great news as it means I can have at least defrost and heat even if the AC portion of the system is absent. However, it only blows out through the bottom vent in the middle of the dash.
If I pull the arm on the actuator beside the vent (pictured in the red circle below), I can shift the air to the upper vents, but it won’t stay there.
Did it require constant vacuum to keep the arm in the lower position to use the upper vents? Is there a way to shift it to the upper vents without constant vacuum? (I’m thinking I may just disconnect the arm and tape it to the position I want if the actuator can’t be adjusted.)
Bonus question, can anyone identify that random disconnected wire indicated by the arrow? It’s way up in there beside the yellow power wire to the fan motor.
I believe that wire is not used in AC-equipped Mustangs and Cougars, but is used in non-AC cars. AC cars have a separate ground wire for the heater blower motor whereas the non-AC cars do not.
I can’t tell you what the yellow wire is. On my 69 there is a yellow wire and it is used. What I can tell you is that there is supposed to be a vacuum hose hooked to the vacuum motor (canister looking thing in the circle). I can’t tell which door it is opening / closing but needs a line hooked up to it from the vacuum switch or another portion of the system.
Yeah, unfortunately most of my vacuum system is MIA, so I think it’s going to be more cost effective to just buy the AC system that replaces everything with electric motors. However, I was hoping to get that vacuum motor shifted, so that it would blow defrost instead of the floor vents for the next six months while I save up for the AC kit.
This is just an example of an available vacuum kit. I haven’t installed mine yet as I discovered the previous guy had hooked things up wrong under the hood :
Most of these systems should default to the defrosters so I’m surprised that the system needs vacuum for it.
Edit: Meant to say, you might be able to pull it into place and put a vacuum cap on that actuator to get it to stay up on the defrosters. Of course if the actuator is toast it won’t hold.
