Air conditioner cold then hot

If the A/C blows cold at first, then gets hot, it may be because there is air and moisture in the system. What happens is that as the thermodynamic cycle of moving heat goes on, water in the system will freeze at the expansion valve, stopping refrigerant flow.

If you put a proper set of A/C gauges on it, the low pressure side would show zero or a negative pressure, while the high side would be >150... Usually low should be between 25 and 45, but because the system is frozen up, nothing moves, so the compressor is acting more or less as a vacuum pump.


Solution:
Have a professional evacuate the system, replace the receiver/dryer, add a bit of oil and then charge the system.

I’m happy to help further over the phone at https://www.6ya.com/expert/jeremy_69f3cc28d95bf514