a/c checks out ok, blows hot

[wbmiller3]

Added some Freon, didn't really seem to need it, gauge in green. Coils in engine compartment are cold, compressor seems to cycle normally (stay's on when selector is set to max, cycle's when temp is turned up) but duct temp stay's around 80 no matter what. Expansion valve? Any thoughts? Not real knowledgeable about a/c systems.

Thanks

 

[stamp11127]

The first step in diagnosing ac systems is the check the static pressure after the system has equalized. Both the high and low sides will be equal unless there is a blockage.

The static pressure reading is equivalent to your gas gauge in the dash. The reading should be close to ambient temp of the engine compartment. It is always better to check it on a cold engine to avoid heat soak in the system.
Then you measure the low & high side pressures after @10 minutes with the system running. This tells you what is happening so you can determine the evap and condenser temps and tweet the amount of refrigerant in the system if needed.

Those cans with the built-in gauge are a joke. Don't waste your money on that junk. What did you add to the system, AC Pro with sealer?