I have a 98 Buick Regal. When my air conditioning works, it is beautiful. On a hot and sunny day when I pull out of the garage, I can run the air conditioning until the car is turned off. After reaching a destination and parking in the hot sun the compressor will not blow cold air. If the day is overcast or cool, the air conditioning works fine. Can you tell me what the problem might be?
Usually, in these cases. you are low on refrigerant. I would see an AC specialist and let him check the system out, recharge as I suspect is needed, and put in a dye to see where the leakage is occurring. It may be as simple as old O-rings, or may be more complicated or more expensive. Get a good diagnosis and then you can make an informed decision.
Does this car have EATC on it? (electronic air temp control)
I’m not real familiar with the Buicks at all but generally the EATC systems use a sun sensor in cahoots with the control head. Maybe there’s a problem in that circuit or the head itself.
If it does have EATC there may be a way to have the thing run a self-diagnostic check and show any codes that may be present. That would require a knowledgeable Buick person, which I am not.
With Fords, it’s just a matter of depressing a couple of buttons on the head at thes same time and waiting for the gibberish to clear.