Let's see if somebody can help me with this- You know the fresh air intake on your ventilation system for ea81 cars? It draws in air above the blower fan. It works by manifold vacuum holding a trap door open (you have noticed the large metal vacuum thing kind of in front of the blower motor). When you move the lever to "CIRC-AC Max", the vacuum is cut off and the trap door slams shut. Here is what the switch/lever looks like from below:

 

 

The black switch is what shuts the vacuum off when the lever is moved, you can see the plate that makes contact with it. This is what it looks like on all the ea81 cars i have dealt with, all 83 and older.

Today I ran into a snag in trying to hook this up on my hatch, in which I have installed a dash that i pulled from a JY literally about 8 years ago. If i recall it was an 86 hatch it came from. The holes are there to mount the switch, but there is no plate on the lever to make contact with the switch. I suspect there was a different switch used on the later year gen 2 cars? I don't suppose anyone knows what i need to do to hook this up?

Solved! they started using a different switch sometime after 83. It is on top of the lever and requires a smaller hose. So to access the old switch, you had to remove the stereo console, the newer switch can be accessed by dropping the heater control face plate.