A/C is not blowing cold air

I currently had my compressor and dryer replaced but the a/c still not blowing out cold air. My friend whose not a mechanic replaced it for me and told that there is still a leak somewhere? What could it possibly be?
Experienced mechanics share their insights in answering this question :
Unless the leak is large enough that refrigerant is just blowing out or somewhere obvious and all at once, the system has to be recharged with a dye installed with it. The dye will leak out with the refrigerant and be visible in a fluorescent green / yellow color under black light. Find the dye glowing and you found the leak.

How to Identify and Fix Common car Problems ?

Our sources include academic articles, blog posts, and personal essays from experienced mechanics :

The most common reasons a Dodge Nitro ac isn`t working are a refrigerant leak, an electrical climate control issue, or a problem with the air conditioning compressor.
If your air conditioner is running, but not lowering temperatures inside, one issue could be a blocked or clogged condenser coil. When operating correctly, the condenser fan draws air into the outdoor unit through the condenser coil to pull heat energy out of your home.
Leaking or Low Refrigerant

If your central AC is not blowing cold air, the refrigerant may be the problem. The unit could be running low and need additional refrigerant added. The most likely cause of this is a leak.

The first possibility is that there is a refrigerant leak. The leak may be found in the evaporator, condenser or hose in which case you should bring your car to a mechanic to be repaired. Another reason that your air conditioner may not be blowing cool air is because the compressor has gone bad.
The most common cause of a vehicle`s air conditioner not getting cold enough is that it needs to be recharged. You can recharge your refrigerant by yourself, but to save time and make sure the job is done correctly you should make an appointment with your local professional auto shop.
An AC refrigerant leak is fairly common but not always obvious. Coolant leaks can greatly affect the efficiency of an HVAC system. Also, when leaks happen, home comfort is adversely affected. Plus, there are certain health issues that could come into play if the leak is not resolved immediately.
First, check your filters and coils for dirt and debris that may be impeding airflow. Once you`ve cleaned the filters and coils, run the air conditioner with just the fan so that the ice accumulation can melt off. If the AC still doesn`t blow cold air, it could be that refrigerant levels are too low.
The most common reasons a Dodge Ram 1500 ac isn`t working are a refrigerant leak, an electrical climate control issue, or a problem with the air conditioning compressor. You may not realize there`s a refrigerant leak until the air conditioner stops blowing cold.
Hissing or Whistling

It could be the sound of refrigerant gas in your expansion valve, for example. But a persistent hissing or whistling sound could be a sign of a refrigerant leak. A refrigerant leak could occur in your refrigerant lines or in your internal valve.

Your car AC may not be blowing cold air for a variety of reasons. Recharging your car`s AC refrigerant or fixing a refrigerant leak could resolve the issue, but complex electrical climate control repairs or a slipping compressor clutch may be necessary to get your air conditioning back to full efficiency.
Typically this occurs due to a bad vacuum check valve under the hood. During hard acceleration the AC door system loses vacuum, causing the doors to default to the windshield. This check valve keeps this from occurring. It is located under the passenger side of the hood.

Relevant Questions and Answers :

the most relevant questions and answers related to your specific issue

Air conditioning blowing mildly cold air on the coldest setting, turned off/on again, now blowing cold air, should it be checked?
ANSWER : If you are getting ready for a long trip and suspect the cooling fan may be not coming on for the radiator and a/c then you should have the a/c and cooling system performanced checked before trip. Nothing worse than breaking down when out of town in a strange area.

Read Full Q/A … : A/C is not blowing cold air

Hot air mixed with cold blows from air conditioning
ANSWER : Hey there. You will most likely have to have a mechanic bypass the heater coolant lines to have this resolved. Your A/C may not be controlling the air flow inside the evaporator correctly out of the vents and may be the blend door actuator stuck in the heat position. Have the AC system diagnosed first before bypassing the heater.

Read Full Q/A … : A/C is not blowing cold air

everytime I turn my car on the ac starts to blow air even if I switch it off. it won’t blow cold air or heat.
ANSWER : Hi there. Based on your question and input, it looks like your AC control switches are damaged, causing the vents to activate even if the switch is not activated. This is sometimes an electrical problem, as it could be triggered by a damaged electrical relay. You might want to have a professional mechanic complete an AC is not working inspection, so they can determine what is causing this issue you’re experiencing and recommend the right repair.

Read Full Q/A … : A/C is not blowing cold air

My air is blowing cold-hot-cold-hot-cold-hot…
ANSWER : It is possible that you have a leak in the AC system. There are pressure switches that will turn off the compressor if the pressure is too high or too low. The low refrigerant level could cause the AC compressor to cycle on and off. If you would like to have this done, a certified technician from YourMechanic can come to your car’s location to diagnose the AC system and make the correct repair.

Read Full Q/A … : A/C is not blowing cold air

My heater is blowing air through the driver side air vents but is blowing cold air through the passenger side and rear console ven
ANSWER : Hi there:

Climate controlled vehicles have multiple electrical relays that open and close vents to maintain the desired temperature. In some instances, these relays can wear out overtime. However, it’s also common for debris to clog up vents (especially side vents) which may restrict the flow of cool air. The best way to determine why your AC is not working efficiently, it might be best to have a professional mechanic complete a AC inspection; so they can pinpoint the source of your issues and recommend the right repairs.

Read Full Q/A … : A/C is not blowing cold air

While driving defroster set to hot blows hot air as it should, while idling it is blowing cold air.
ANSWER : First, the coolant level should be checked to make sure the radiator is full. While the overflow tank may be full, the radiator cap must be taken off to check the level inside the radiator. If you find the level is very low, you have a coolant leak that must be fixed. If coolant levels are normal, an engine thermostat or heater control problem may be what you’re experiencing. Consider hiring an experienced technician like one from YourMechanic who can come out and take a closer look at your lack of heat concern to offer a more personal diagnosis.

Read Full Q/A … : A/C is not blowing cold air

I have a 2006 dodge charger 2.7 that has been overheating and the heater is blowing out cold air, warm air, and sometimes hot air
ANSWER : Hi there:

Overheating issues can be very difficult to pinpoint without completing a physical inspection. If your heater is not blowing warm air, it’s very possible that you have a clogged heater core coolant line; which can cause engine overheating or the heater core valve is damaged; which can also cause the same situation to occur. It’s best for you to have a professional mobile mechanic come to your location and complete a car is overheating inspection so they can pinpoint the source of your issues and recommend the right repairs.

Read Full Q/A … : A/C is not blowing cold air

Air conditioner blows hot air on the left side and cold air on the right side
ANSWER : A common issue across many makes and models with dual AC in the temperature blend door actuator failing and causing drastic temperature differences between the driver and passengers sides. Have the HVAC system inspected by an experienced professional to find the specific cause. A certified professional from YourMechanic can come to your car’s location to diagnose the AC and assist with proper repairs.

Read Full Q/A … : A/C is not blowing cold air