I know I already said this, but have a shop vacuum down the system and charge it with the correct amount. I use to fill them with a can, and then let some out till compressor ran all the time at idle. Worked good for the most part, until there comes along a 100 degree day, and it don't work. Why, because pressure switch says there's a problem and compressor shuts down. They need to be vacuumed to get any air and water out of the system, because like I said they only hold a small amount of Freon (1 or 1.1 pounds).