Air conditioner not blowing cold on passenger side

I took my car in to have the a/c checked out. The passenger side was not blowing consistently cold air. Driver side ac would work only if the car was cold, taken out of the garage. Once exposed to the heat outdoors and started up again, only moved existing air about. The mechanic said I needed new freon. He took out the old and replaced it. The system blew a little colder, but the temperature level is not being met and the outside temp reading is way too high. What do you think is wrong with my car. Now the same mechanic (who supposedly did a "free"diagnosis of the original problem) wants to replace my blend door activator ($265) plus his labor ($300). What do you think is wrong with my car? BTW it’s a cream puff with only 49,000 miles.

Well your description does sound a lot like a blend door, although I would not assume that is correct.

What year park avenue is it? Older cars tend to have old rubber vacuum lines and those old lines can cause the blend doors not to operate correctly.

I would suggest finding a real AC shop. Likely they do radiators as well. Let them check things out. They will likely also be good at blend doors.

thanks for the tip. The car is a Buick Park Avenue, 1999 with 49,000 miles on it. In every other respect she is a cream puff. I had my doubts when the freon was exchanged,but thought that perhaps it was something that needs to be done sometimes. I’m not mechanically inclined at all.
After the replacement of the freon, the cold air was still not circulating on the passenger side or to the back seats. When the car starts out right from the garage, the system seems to work great. It’s only after she’s been parked and I need the ac on again, that the cold air doesn’t kick in.

It might be the blend doors, but it sounds more like an air temp sensor or the control head. You need to go somewhere that can do good diagnosis and not just guess at it.

To begin with, the a/c system must be analyzed completely and properly. Pressure readigs etc. That system is closed. Theoretically, you would never need to add freon but vibrations and so on can create minor (or major) leaks over a period of time.

What you need first is a new mechanic. “Old” freon?

I agree with “tardis”. Not enough input concerning the symptoms.

Take it to a qualified a/c shop and make sure that the system is working properly before starting to suspect blend door problems.