AC Actuators and Antenna Plug

Q: AC Actuators and Antenna Plug

As I am taking apart the front end of my bird, I have found two things and I don’t know what they are. One is come kind of canister and the other is a strange wire, like a plug or something. I took pictures of them so you can see what they look like. If you know what it is please tell me about it.

A: The canister is the vacuum reservoir for your AC system actuators (Fig s2.jpg). The plug appears to be for your radio antenna (Fig s1.jpg).

A: The one in the door jam looks like a antenna wire. The can with the vacuum hose looks like a reserve vacuum can. I took one of those off of a 7# Nova when I removed the A/C system. It was used to add additional vacuum to the ventilation controls.

A: The AC actuators are actually only used for the COLD IA position of the heat/AC selector. This actually means “cold inside air” and is just to the LEFT of the COLD position. In this position, the heater core is completely bypassed and the AC compressor is on with air recirculated from inside the vehicle. There are two vacuum pot actuators which are plumbed with a tee in parallel: One for the cowl plenum, which is a normally open spring loaded flapper that shuts off the outside air intake. It is located on the passenger side of the cowl area under the cowl grille and basically blocks off the cowl area to the fender side of it. The second one is in the passenger side kick panel vent which is normally closed. This one opens to allow inside air to be drawn (sort of backwards) into the AC evaporator intake. The position to operate on outside air is called COLD OA, which is just to the RIGHT of the COLD selection. This is where the actuators are switched off from the vacuum source and springs open/close them to their relaxed positions. About halfway between the COLD and the HOT selection, the compressor switch shuts off (temp. door is also allowing some intake air to the heater core after it passes through the evaporator, giving you a mixed temp.) All the way to the HOT postion allows air through the (now ambient temp. with no compressor) evaporator and then fully through the heater core for hot air. Incidentally, the kick panel flapper actually replaces the manually operated one that is used for non AC cars. There is a domed plastic cover (matches kick panel color and texture) that covers the vent so that the actuator is protected. COLD IA is like the MAX AC or RECIRC positions found on cars today; the air from inside the car is recirculated for those hot sweltering days like we have here in Maine for about a week out of the year :). If you don’t install the actuators, you won’t get the “MAX AC/RECIRC” and I’m not sure of the performance. Anyone know for sure? (I’ll bet it’s sufficient for us Northern folks without it).

P.S. The VENT position allows the plenum to open and the kick panel recirc to close in their relaxed states. The compressor is off and the heater core is bypassed. You just get outside air coming in through the (ambient temp.) evaporator and into the AC outlet distribution. Hope this helps.

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