My 2010 F150 Lariat AC has been working been working on and off as of late. When I was having my oil changed the technician tested the freon charge and said it was overcharged. I've owned the truck for 3 years and have never added any. Any ideas what would cause it to overcharge?

 

The ONLY thing that would cause an overcharge would be adding refrigerant. Since that wasn't done, the "technician" was probably mistaken.

 

Did he tell you what the low and high side pressures were? What was the ambient temperature?