Air conditioner blowing warm air. Heat blowing warm air. Neither hot or cold

My air conditioner is blowing warm air. It blows hard but the air is warm. But then when I turn on my heat it does the same thing. Warm air not hot. I figured it was out of refrigerant but it's full… help please!!

My car has 195000 miles.
My car has an automatic transmission.

Experienced mechanics share their insights in answering this question :
If the A/C system is full and pressures are reading correctly, and the cooling system is in proper working order (thermostat opens, no overheating, etc.), then most likely the problem lies with the dash. The climate control head unit may be at fault. One or more blend doors behind the dash may be stuck or broken. If you’re unable to fix this issue yourself, consider YourMechanic, as one of our mobile technician can come diagnose the issue with your A/C firsthand and help you fix it accordingly.

How to Identify and Fix Common car Problems ?

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

Head to Firestone Complete Auto Care for an A/C performance check and recharge. What`s making my 300 A/C put out warm air? An A/C blowing hot air has several possible root causes. There could be an issue with your compressor clutch, a blown fuse, a leak, or a clog in the expansion valve.
A car A/C blowing hot air is often the result of a refrigerant leak. Refrigerant is a liquid that circulates through your car`s A/C system, expanding and contracting as it removes heat and humidity from the cabin. None of the other A/C components will function correctly without proper refrigerant levels.
If your A/C flip-flops from hot to cold and back again, your expansion valve could be failing. The expansion valve removes pressure from liquid refrigerant to allow expansion from a liquid to a vapor state in the evaporator. If the valve is blocked, the refrigerant flow could be restricted or could be too unrestricted.
The most common reasons a Chrysler 300 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.
Turn the ignition key on, but don`t start the car. Press and hold both the power button and the recirculation button at the same time. Hold them for five full seconds, then release. You should hear the climate control system resetting.
The most common reasons a Chrysler 300 heater isn`t working are a broken heater blower motor, a problem with the thermostat, or a failed heater blower motor resistor. Search our network of RepairPal Certified shops near you to speak with a technician about your issue. Oops! We got lost!
The most common causes of broken air conditioning are leaks or compressor issues. If your air is blowing cool but not cold, the problem could be a clogged filter, cooling fan problem, radiator trouble, or it could simply be that you need to recharge your AC.
Dirty Condenser

Debris such as sticks, twigs and weeds can affect the airflow of your outdoor AC unit (condenser), causing it to blow hot air. Dirt and debris buildup is a common cause of a “No Cool”, and sometimes a simple cleaning of the condenser is all it takes to get your cold air back.

Low or Leaking Refrigerant

If there is a leakage in the coils or refrigerant lines, the refrigerant level in the cooling unit will decrease, resulting in warm air blowing from your vents or even reduced cooling performance. Over time, the refrigerant leaks can lead to low refrigerant levels.

Air conditioners use fuses as a way to protect the condenser from being exposed to excessive amperage. Fuses are designed to handle a limited amount of amperage based on the maximum amount that the unit is rated for: If more amperage passes through, the fuse will blow to protect the condenser from overheating.
SOLUTION: Remove any sticks, small rocks, etc., from the grille. This simple DIY action might stop the problem of your AC blowing hot air. If not, take the car to a body shop. The system may need flushing or mechanical repair.
There`s a Refrigerant Leak

When there`s a refrigerant leak, the AC unit loses some of its ability to cool the air in your home. If the leak is large, the AC may begin to blow hot air abruptly, whereas if the leak is small, the transition from cool air to warm air may be gradual.

Relevant Questions and Answers :

the most relevant questions and answers related to your specific issue

Air conditioner blowing warm air. Heat blowing warm air. Neither hot or cold
ANSWER : If the A/C system is full and pressures are reading correctly, and the cooling system is in proper working order (thermostat opens, no overheating, etc.), then most likely the problem lies with the dash. The climate control head unit may be at fault. One or more blend doors behind the dash may be stuck or broken. If you’re unable to fix this issue yourself, consider YourMechanic, as one of our mobile technician can come diagnose the issue with your A/C firsthand and help you fix it accordingly.

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.

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.

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.

Overheats When Blowing Warm With Heat & AC But Not When Blowing Cold AC
ANSWER : Hello, thank you for writing in. There are so many different codes being triggered, that it is unlikely all of these systems are having issues at once. We need to focus in on the fact the engine is overheating at all. You will want to check the level and condition of the coolant and the overflow tank. If the level is full then you may have an issue with the thermostat, radiator cap, or water pump. These can all be tested and changed relatively easily. If the main cooling system is okay, you will want to look into the heater core and climate control module. For more diagnostic help, contact our service department to schedule an appointment.

Air conditioner blows hot air. 1995 Mercedes-Benz E300
ANSWER : Hi there, thanks for writing in about your 1995 Mercedes-Benz E550. This could be a variety of issues, such as no pressure or low refrigerant levels, a bad compressor clutch, or a compressor not engaging correctly. Check to see if the cooling fans are on when the AC is running. Most systems are designed to have them run when the AC is on. Also, check to be sure the compressor is engaged. Look to see if the pulley is spinning when the car is running with the AC on. If you need help with this, a qualified professional from YourMechanic can come to your car’s location to inspect the AC system and pinpoint the necessary repair.

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.

When idling, car overheats and A/C blows hot air – 2001 Saturn L100
ANSWER : Hello. The most likely cause of the issue that your are having would be a faulty cooling fan. The cooling fans purpose is to keep the radiator and condenser for the air conditioning cool during the idling function of the vehicle.

If the cooling fan is not working, this will cause the radiator and condenser to get very hot. When the radiator and condenser get hot, this can cause the vehicle to overheat and the air conditioning not to work. When the vehicle is driving at higher speeds, the force of air that is created towards the vehicle will flow through the radiator and condenser and therefore keep them cool. I would recommend having the cooling fan checked to make sure that it is working properly. If not, I would recommend having the cooling fan replaced.