No sounds coming from anywhere under/in the dash.

 

The vents under the dash are molded plastic, I don’t recall any hoses , so I don’t think there’s any need to get in or under the dashboard. Most likely just a Freon issue, best to have a professional shop handle that.

 

A couple of things:
Thanks Donbrew for sending the illustration. Don't know if I'm gonna go that deep into the weeds, especially considering good advice from Oldblue and firemangeorge about keeping clear of the dashboard airbag.
This is puzzling though. There doesn't appear to be less airflow from the driver's side vents (left & center left), just less cold air. The passenger vents are much cooler, with the far right one blowing what would be considered "air conditioned air," fully 20-25° cooler than the ambient temperature, so I'm not sure it's a refrigerant issue.
Thinking back, the whole instrument cluster was replaced when I first bought this car because the odometer wasn't working. This happened last March when the entire country was getting shuttered because of Covid-19, and given present circumstances, I can't help but wonder if over the past 15 months, something the repair shop did — and may have done a little hastily to get projects out the door — has come undone.

 

Replacing the cluster definitely gives opportunity to disturb the duct work. Looking at the diagram you will notice that the right side is much shorter than the left.

 

If the same amount of air is coming out, it's won't be a leak, and even if there was a leak, the duct is pressurized so it would leak cold air out and there would be less flow. More likely one of the mixing valves is not quite closing allowing hot air to leak into the ducts and the location of that leak is causing one side to be hotter than the other. Or that's what I'd guess. Try turning the fan on high and cycling through every position on the controls a few times to see if it changes.

Ira

 

Thanks Ira.
The fan's been on every position/speed available and nothing's changed. But I'll try again.
Moving from Left to Right, the four vents go: almost cool -> almost cool -> cooler -> cold, with "cold" being the temperature one would expect from the A/C being on.
You could be right about a mixing valve. Is there any way to test or analyze whether this is the culprit, and if so, is it something "fixable," or would it need to go to an A/C shop because of the repair complexity?

 

it could be actuator #5 not functioning or #6

 

It could potentially also be #4 if recirculated air went mostly to the passenger side. Can't really tell from the pictures how the valves route the air.

Ira

 

Is recirculated, conditioned air not as cold as fresh, conditioned air? I would think it would be the same, or at least very close.

I would think the temperature actuator would be most likely.

OP, what happens when air is directed to the footwells only?

I think the heater hoses enter the housing more towards the driver side. Same side as the temp actuator/door. So maybe that door is stuck open very slightly.

If it was a bad mode actuator, wouldn't air be directed to vents that were not selected by the knob?

 

The blend door for temperature controls the air flow over the heater core or the A/C . I would suggest testing that first .
In Sweetie’s old Sunfire, it had a similar HVAC system, I changed that actuator motor, and that resolved the issue.