Why Your AC Blows Hot Air On Passenger Side?

What if you are driving in your car taking your friends out for a ride in the summers? You turn on the AC in your car and suddenly all your friends start cursing you for the warm air your AC started to blow to their side, but you are unable to understand since you are getting the coolness of the AC. Which resulted in a fight among you all and your trip got spoilt.

But that misunderstanding only happened because of the AC showing double standards, which was blowing cold air on the driver’s seat but hot air on the passenger seat. Why would your ac blows hot air on passenger side? Let’s find out.

Reasons Why Your AC Blows Hot Air On Passenger Side

Usually, cars that blow cold on one side and warm on the other side, are typically provided with a dual-zone climate control system. Dual-zone systems make the driver and front passenger adjust temperatures as per their comfort levels. There are two main reasons why your AC blows hot air on passenger side and cold to the driver’s side that are

1. Low Refrigerant Value In AC

Low freon level in your car’s AC could be the problem if your AC system stopped blowing cold air. As the air conditioning in your home, automotive AC systems work by using freon to cool air. They are stable, nonflammable, low toxicity gases or liquids which have generally been used as refrigerants and as aerosol propellants. The compressor pressurizes the freon, turning it from a gas into a liquid. Change in pressure allows the air around to cool down.


Leaking gas is one of the main reasons for the low level of refrigerant in your car’s AC. Symptoms that your freon is leaking:

  1. One of the most characteristic symptoms of low freon is the presence of room temperature air blowing from the vents. If your ac is throwing away room temperature gas instead of a cool gas then it definitely means that your car’s ac is not leaking freon gas.
  2. If you notice anything grease in liquid stater around the compressor, lines, or inside the cabin then it could be freon Of course, another sign of low freon levels is a visible leak. Freon usually looks like thin grease in a liquid state.
  3. If your clutch is not engaging then it is a sign of leakage because the clutch allows the compressor to pressurize the freon. The clutch works by reading freon levels. And if there’s not enough freon, it won’t engage.
  4. The presence of ice on the compressor could indicate low freon levels which are generally caused by moisture taking the place of freon.

HVAC Door Issue

In most vehicles, the blend door hangs on a vertical or horizontal axis, The temperature is manually controlled by a slide lever or switch on the HVAC control panel. This slide lever was connected by a cable to the blend door. Sliding the lever to the left or right make you chose between cold to normal to warm air. So turning a corner or changing the fan speed can cause a broken blend door to randomly swing between the hot and cold positions.

Dual zones supplying different temperatures from vents on either side of the dash are achieved by the use of small doors within the HVAC housing. By controlling the doors, the temperature of the air on the left and right can be adjusted to the desired comfort level. Many times the motor (or actuator) that controls the door for either side can fail or the door itself can break and prevent the temp from being adjusted.

How To Fix Your Car’s Ac?

The good news is your AC can be repaired on your own without any help from your mechanic.

These are just a few common signs of low freon levels. The good news is that you can usually recharge your vehicle’s freon yourself, without the need for a professional mechanic. With that said, however, this is only a temporary solution if there’s a leak. Unless you find and fix the leak, the newly recharged freon will likely leak back out. So, find and fix the leak, and then recharge it with more freon.

As much as you want to refill the freon yourself, you should be hiring an assistant who is an expert in doing so since refilling the freon yourself can be a dangerous task if you are unaware of how to fix an ac by yourself. The cost of recharging your home air conditioner depends on the cause of the leak. Similarly, the costs of buying Freon for an A/C and having a professional refill will depend on your service provider.

In the case of the HVAC door, the procedure can be very time consuming, that involves lowering the steering column, removing the dash panel, clearing the AC system, and disengaging your evaporator after that you need to drain the cooling system and disconnect the heater core after following these steps you are ready to remove the HVAC door. Once the plenum is removed from your car, the only thing you have to do is to replace it. With the use of proper equipment and proper instructions you can easily repair your Car’s AC it may be time-consuming but not a difficult procedure to perform.

But it is advised that you hire an expert rather than doing the process yourself since replacing an HVAC door can be a complex process and can be dangerous if you mistakenly forget any step. The cost to replace an HVAC system averages $7,000, with a typical range of $5,000 to $10,000. This means from $25 to $60 per square foot, depending on the brand and size.

How To Prevent Your AC From Damaging?

Some easy steps to prevent your ac from damaging are as follows:

  1. Timely clean the dirty air filters and replace them if necessary.
  2. Diagnose any problems such as holes in any ducts, from time to time, and repair if your find any.
  3. Clean the dirt and debris from the outside unit.
  4. Regularly go to an automotive expert for a routine checkup, don’t take the routine checkup lightly.

These are some steps you can follow to prevent any damage that may happen, to your car’s ac. As we all know prevention is better than cure.


In conclusion, you might say that if your car blows hot air to passenger side you now know what is the reason and how you can prevent the situation. Now you also know how to fix your car’s ac if such a situation arrives, also it doesn’t even cost much if you go to a repair center, so if you are unable to perform the procedure yourself then you can take your cars to an automotive expert he will do the work for you.

Hopefully, your queries are resolved, if not comment down your question below in the comment box.

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