If anyone suspects their a/c just isn't cooling like it should can check it themselves for the cost of a digital or analog thermometer that can read from say 30 degrees F on up. Not one used to check human temperature.

Step 1. Find out what the outside air temperature is for where you are. Weather.com. national weather service etc. Make note of the temp.

Step 2. Close windows, start your X and put your a/c blower on 4, make sure you have the air source set to recirculate, and make sure your temp controller is all the way on cold.

Step 3. Insert the thermometer into one of your vents, preferably one of the center ones and rev the motor up to maybe 2500-30000 rpm.

Step 4. Note the temperature on your thermometer of the air coming out of the vent. If your air conditioner is blowing air that is 20-25 degrees(30 degrees lower than OAT in a perfect world would be ideal)lower than outside air temp, your vehicle's a/c is working fine and is doing as good as it can.
Example if it is 85 degrees outside and your X is blowing conditioned air from the inside vents is between 55-65 degrees, you are good to go.

Without a/c gauges, this is the next best way to troubleshoot a/c problems. On the helicopters I work on, they use an A/C system very similar to a car, down to a Sanden compressor. After we service our aircraft with a weighted charge of R-134 we use the thermometer method to double check cooling efficiency. Hope this helps.