This is good logic. Your system has been working for 2 years after you replaced that switch. It isn't the first time a new part has gone bad.

 

Why flush the system/ add oil and new freon? It's worked fine for years. How can it be overcharged if nothing has been done to the system also ?

 

Reread his posts, he added refrigerant. It's a common mistake made to remedy a poorly performing system.
And apparently it has not worked fine for years, hence this old thread.
Because there is no way to know how much oil is in the system presently or how contaminated it may be, and you can polish the existing refrigerant and reuse it.
He only owned the car for 4 months before it failed and there is no telling how much the system was cobbled up before he got it, if at all. Many are, just for the sale.

Why would you replace a pressure switch if the compressor is still running as he has stated.

And I did say "may be correct".
It's impossible to give a definitive cause with the info provided, but one can guess all day long.

 

Tiapetra I think your probably right about it being the expansion valve acting up. Two years ago I mention the control valve in the compressor because I thought it was a CVC type compressor. Mine actually has one of the PXV16 compressors and have been told those either pump or don't. And about it being overcharged I didn't add but just a bit back then and was monitoring pressures the whole time to make sure it didn't get to much in. The AC today will work shortly when you first crank the car with pressures today being between 45-50 on the low side and high side reading about 210-220 and outside temps are right around 100 degress today. When it stops the low side pushes close to 100 and highside drops to about 160 today. since I have to open the system up Im just gonna replace compresser, condenser and expansion valve. Oh and I had tried the hammer trick Tiapetra

Ill give an update once I get everthing installed and recharged.

 

Just for fun, try and clean the compressor clutch with Brake Clean or similar.
Your pressures may also indicate a slipping but not completely disengaging compressor clutch when it warms up and loads.