Quick and dirty test is to feel both A/C lines at the firewall: are they the same cold or is the one going to the compressor warmer than the other? If so it's low on charge.
The factory books call for these systems to be evacuated and charged by weight. Part of the reason is there is ~1/4LB of refrigerant in the accumulator that is a leakage reserve and for system load changes. That wildcard in the accumulator is difficult to see with gauges and temperatures. The system will actually blow colder if there is less refrigerant in the accumulator, but, the compressor is starving for oil under that condition.
This is why you evacuate the system, pull a vacuum, and charge it by weight Vs. toss a can in and hope. The cost of the can you may waste is ~1/2 the labor to an A/C shop to do it right the first time.
Inspect the A/C system for any oil accumulations on connections. These would indicate a leak.
The engine cooling fan with an aged out fan clutch and crud clogging the condenser and radiator is often overlooked because the engine isn't puking coolant overheating. If the fan clutch is at or over 5 years old it's past it's best if used by date. Replace it with an OEM clutch. One more time spend the money on a MOPAR clutch not a hack aftermarket clutch. (Obsolete parts may not be possible to get OEM.) Fan clutches loose 200 RPM per year and 5 years is 1000 RPM slower. All the heat coming out of the cab has to go somewhere! A slow cooling fan makes the A/C system suffer and not cool as well.