Have your friend to recheck the A/C pressures.
Since the system has not been in use the pressures on both the low and high sides should be the same. If so this means that there is no blockage in the system (this would be good).
If the pressures are too low, put that can of R134A in and see if the system starts to cool.
Let me know what happens.
Wednesday, July 30th, 2014 AT 7:38 AM