Okay, I just got back from my shop. I pulled the vacuum connector off the HVAC controller (that little retainer disc is AWESOME!!! *lol*) and tested all lines positive. Each holds vacuum as it should, actuators are moving nicely.
Obviously I could not test the vacuum source as engine is not running. Where exactly is the vacuum drawn from the engine? Id like to test the source line for integrity but have no idea where it ends on engine side.
So... No potential noise source found yet.
The heater core housing is nicely accessible now, next step will be to remove the coolant hoses and pull it out 👍
Well... IMMEDIATE next step will be to prepare a home made pizza and empty some bottles of beer. Cheers!
