Dual Climate control
 

I have a 2006 S80 2.5T the air conditioner works when it wants to. I took it to a mechanic and they said it was the dual climate control panel so i replaced it and it is still doing the same thing

Your post is akin to someone saying ' I sent a letter to someone and they never told me they got it".

You see, the basic info is there but not something that would help anyone understand what the problem is and, really, exactly what was done. Not a prob, but please let me ask a few questions I have.

Have you owned the car long and how many miles on it. Any other issues and/or trouble codes, with it?
Was the air conditioner working in the past? How well was it working.
When was the system last serviced and by whom (prior to this issue).
Who is your mechanic? (not a name, a dealership, independent Volvo garage, a Pep Boys type center, a gas station, etc?)
What sort of control panel did he put in - new, used.
Exactly what are the symptoms, -"works when it wants to" is rather vague and in my limited experience, the panels are not sentient and so are incapable of independant thought and action. But it can seem taht way. Is the fanthe issue? Not cooling? If so is it acroos the board (heat,
cool, defrost) or temperature dependent?

My experience with Volvo AC issues are not to go looking at the control panel to be honest. That my be your issue (but it seems to be less likely now than before the work was done, right?)

Low on freon is always the first place I would look, followed by the operation of the compressor clutch, and I would look at the fan control after that - these are things that are more likely to fail on a 100,000 mile + car that is 14 years old.