hey Scotty,
I drive a 2018 Altima with just over 100k
The AC is blowing but not cold at all.. (only at night) I was told I need a new compressor and to shell out $1,400.00 that I don't have right now.. im pretty handy . I know its not leaking. & the refrigerant is plenty full.. do you think its just the Compressor control Valve that needs to be replaced?
The rockauto.com parts database does not show a separate control valve available for that compressor. It may be a dealer-only item, or integral with the compressor and not replaceable.
You really don't know if you have the correct amount of refrigerant unless it is evacuated and recharged with the proper amount. On modern vehicles with variable-displacement, computer-controlled compressors even a few ounces one way or the other can throw things off.
The problem is that this could be a mechanical problem or a computer problem. It's even possible the AC is actually working but your blend door isn't and is preventing cold air from reaching the vents.
It appears that compressor has both a clutch and a control valve. Is the clutch engaging when the AC is turned on? What are your high and low system pressures while the AC is running? That at least would provide a clue as to whether the compressor is pumping.
Air conditioning systems these days are very complex and require not only the usual AC tools like a manifold gauge set, but also a professional-grade bidirectional scan tool for troubleshooting.
I just had this issue with my Altima (2014). One thing that I noticed with it is that some wiring that provides power to the AC system was torn off, located by the radiator. Once my mechanic replaced that piece, the AC blew cold. My best bet will be to check for the wiring and that could do the trick. Good luck!
