Car ac problem

hi, I have Nissan Tiida 2009, I recently replaced the compressor, The AC is blowing cold air now, if the car is standing still and I turn the AC on, everything works the way it is supposed to I have checked the fan speed also, all is ok but once I start driving on the main Highway after a while it feels like the Ac is not throwing enough air, its not like it stops cooling because if I put my hand near the vents, It is still cold around that area but at that point even if I increase the fan speed to max the throw of air remain the same. it becomes so less that I start sweating. can any one tell what could be the problem here.

check the charge on the system. hope you had the accumulator/drier replace along with the compressor. it is recommended replacement anytime the system is cracked open.

second step could be you have a clogged up condenser, that is not allowing the function to work at max

Are you saying the air flow from the vents decreases as you start driving as compared to when you’re idling? If so, it sounds like a blend door problem, especially if your blend doors are vacuum operated, but I’m not sure that they are.

“if I increase the fan speed to max the throw of air remain the same” Fan speed does not increase? If not, then probably the fan or the controller is not working. There is also a blower motor relay that you could swap that provides power to the fan. The control unit head controls the fans speed. This is a manual unit or is it and auto controller.

The evaporator may be icing up due to the drain being blocked.

I agree that the evaporator is icing up, but I suspect that it is more likely due to an undercharge of freon and/or the air was not evacuated before the system was charged. It is also possible that you have too much oil in the system. You have to drain all the oil from the old compressor and measure the quantity. The subtract the amount you drained from the old compressor from the amount specified for the system. Then you have to drain the result amount from the new compressor before installing it.

I.e. if the system specifies 50 cc of oil and you drain 45 cc of oil from the old compressor, that means there is still 5 cc of oil still in the system. You have to drain 5 cc of oil from the new compressor or you will have too much oil in the system.