Yes, the other vacuum functions would still work as they are supplied before the climate control. They would be a bit slower but since they are supplemented by the vacuum reservoir you probably wouldn't notice the delay.

The fact the fan doesn't engage using the defrost function casts doubt on the pods being the problem. Might be worth checking them out while you are in the process.

You say you removed and checked the CCU. Are you referring to the push button unit mounted in the console?

The actual control/amplifier is located in the right hand side of the dash behind the glove box. Is that the part you checked? There is a relay located on the cabin side of the firewall also located behind the glove box. That might be what you are hearing "click".

To eliminate the pods causing the trouble the easiest way is to remove the glove box and physically observe the movement of the diaphragms. Obviously the vehicle need to be running. The micro-switch is located on the ducting to the right of the main duct work where it joins the center air box.

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