1971 A/C 3 Port Vacuum Selector Switch - Correct Routing

[FrankC]

As a follow on to my thread - I obtained another A/C controller for parts, but this unit has 3 vacuum ports, instead of the 2 on my truck.

I searched and found this diagram, but would like to know from the board members, what port # this switch is oriented to.

In other words -

the vacuum line for the ball to the selector is #n
the vacuum line to the heater valve is #o
the remaining cowl and recirculating air port is #p

Let me try to upload this diagram.

Frank

[mikemileski]

Here's the two port diagram. Look at both next to each other and you can probably figure out what to do. Not sure what you mean by #n, #o, etc.

Mike Mileski
Tucson, AZ

[FrankC]

Hi Mike,

Thanks. Each port is labeled #1, #2, and #3 on the selector switch.

So the question revised is:

1. Vacuum Resevoir to Port #1 or Port #3
2. Water Valve to Port #1 or Port #3
3. Outside Air is Port #2.

Really, the only difference is that the Water Valve is separate on a 3 port.
On a two port - it is connected via a 't' between the Outside Air Diaphram and the Water Valve.

Frank

[stich626]

this I want to see. my heater,a/c control has three ports with one pluged..

[FrankC]

I plugged Port 3

Used Port 2 for the under-dash vent, cowl vent and heater valve.

Port 1 for the Vacuum Ball.

Worked just fine - so I think that is solved.

Question: Should there be a spring on the right hand vent door between the bracket of the diaphragm and the vent door?

[dadsworktruck]

here is a picture i found,i wish these pictures showed bolt sizes and part numbers too, but i guess that would take all the fun out of hunting....don