Yes I searched. I think my issue is too specific for the threads I found.

Whistling from HVAC only when A/C is invoked. If I hit EC it goes away. If it's cold outside and heat is being invoked it goes away. But when the set temp is reached and the HVAC goes into maintenance mode it comes back. It is LOUD and can be continuous, uninterrupted whining/whistling noise while driving.

I suspect it is an A/C blend flap vacuum pod. I know the sound of a vacuum pod, I already replaced one on this car a few years back to solve a very similar noise.

I've removed glove box and passenger under-dash and tunnel panels. Removed vacuum line from each accessible pod and plugged, none of which made the whistling go away. I believe there is another pod that I can't see (?) possibly behind the radio? It sounds like it's coming from in there.

Any ideas?

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