What are the correct Pressure gauge readings for low and high side of the A/C system? I have a 2007 STX special edition with the 5.4 3v. When I hook up the gauges and turn on the A/C to #3 so it will cycle. When it kicks on The low drops to 22PSI and the high goes up to 175psi then when it kicks off the low goes up to 40 psi and the high goes down to 125psi. Does that sound right? I live in the south and the system works great in Ga but when I came down to Florida it doesn't get near as cold.
Here is a picture of the gauges with the truck off and its 80 degrees right now.

 

It seems like it might need a bit of R-134a. The compressor should run near constantly when engaged.