Adding too much refrigerant to the lines of the AC system is what causes it to overcharge. It is for this reason why the recommended route is to have a professional recharge the car AC. Once an overcharge happens, the system no longer does as it is designed to do, blowing cool air.

If your AC isn’t working because the system has been overcharged then the most obvious solution to the problem is to remove some of the excess coolant that’s been pumped into the system so you can get back down to the normal pressure that you’re supposed to have.

Although mechanics tell owners that the high pressure is due to a problem with the accumulator or evaporator that is not likely the case. Most high-pressure readings are a result of the freon or refrigerant not cooling adequately. Insufficiently cooled freon automatically causes the pressure to increase.

Signs of a Frozen AC Coil

1. AC unit runs but doesn’t emit cold air.
2. Ice is visible on the indoor or outdoor coils.
3. Visible extra moisture/condensation around your AC system or home.
4. Ensure the air filter is new and clean.
5. Turn off the thermostat setting and turn the fan on.

You should replace these about every 90 days, if you have no allergies, but AC pros typically recommend every 45 days for max efficiency. Be sure to replace them with the right size and type of air filter. If your AC was working properly, you could remove the filter and buy one that is identical to it.

Your air conditioner will run without a filter, but you shouldn’t try it! Without a filter, you leave your system wide open to all types of dirt and debris that will damage the HVAC system and lead to expensive repairs.