Front AC Not Working But Back Is – Why Is That?

Just like other parts of the car, malfunction is inevitable with the AC system.

If you have the problem of the front AC not working but back is, you should not panic but proceed with the necessary analysis to find out what detail is functioning improperly.

Changing the components without inspection can lead to a waste of time and money.

Therefore, I’m here to help with our guide to determine the cause of the front AC vents not working and how to address it.

How Does The Car AC Work? 

front ac not working but back is

How Does It Work?

The AC system consists of various components, such as an engine-powered compressor, an expansion valve, an evaporator, and a condenser.

It transforms the refrigerant’s state from liquid to gaseous and back and regulates the airflow, creating moisture and heat; thus, the cool and dry air comes out from the air conditioner.

What Does The Car AC Consist Of? 


The AC condenser cools the high-pressure gas, which was warmed into a liquid state. Its curved shape and small fins allow the heat to release faster.


The AC compressor moves the heat inside your car in the refrigerant cycles. The issue of A C not working in the car might happen if you have a faulty compressor.

Compressor Clutch

The clutch obtains a pulley rotational mechanism (by linking the compressor and the engine speed with the V belt), ensuring the compressor’s function and creating continuous rotation when the AC is in use.


The evaporator changes the status of the liquid form to gas (so it can evaporate) and absorbs heat from the high-pressure gas passing through the expansion valve.

Expansion Valve

The expansion valve decides how much refrigerant goes into the evaporator each time and adjusts the temperature of the high-pressure gas emitting from the evaporator.

Pressure Switch

The pressure switch, connected to the compressor, regulates the pressure of the cooled-down high-pressure gas.

Filter Drier

Water in the refrigerant can cause a freeze in the expansion pipe; thus, it needs to be filtered out by the filter drier.

Plus, the component also blocks dirt, air ducts, and other contaminants from entering the system.

Ventilation Blower

The blower blows the air into the vehicle at an angle to the incoming heat-absorbed air. If your AC blower is not working in the car, you may not feel any air coming out at all.

High-Pressure Service Connection

This safety tool will be activated when the refrigerant’s pressure is too high.

Front AC Not Working But Back Is – Why This Happened? 

ac works in back but not front

If you have low refrigerant, a faulty motor blower, a broken fuse or bad relay, clogged vents, or an issue with the compressor, your AC won’t blow out of the front vents.

You’d better identify the underlying problem correctly to have a proper solution.

And remember to troubleshoot it as soon as possible to prevent further system deterioration.

Low Level Of Refrigerant Or Leakage

The situation of the front AC not working, but back in Chevy Tahoe can result from insufficient refrigerant.

If there’s not enough of this chemical substance, the air can’t be circulated through the cabin. The refrigerant level will reduce after a long time using or due to leakage.

I noticed the cooling quality of the air was affected and experienced AC blowing weak in the car or even blowing hot air.

Besides, refrigerant leakage is also one of the potential reasons why an AC compressor shuts off after a few seconds.

Broken Fuse Or Relay

A broken blower relay can prevent the blower motor from working properly. When the motor has no blowing, it will lack ventilation.

Since almost no air goes through the vent, the AC doesn’t turn on in the car.

In this case, I checked the fuse box to identify if it was the cause of the issue.

Faulty Motor Blower

The component is actually a fan behind the dashboard and is in charge of blowing air through the vents.

When this crucial part of the car’s ventilation system fails to work (can be due to long-term use or electrical issues), it leads to the issue of the AC not blowing air into the car.

In addition, the motor works with the help of the blower resistor. The resistor regulates the flow of the air or the blower motor’s speed.

When you rotate the speed dial, the resistor module will receive the signal from the climate control module and adjust the speed of the electrical current flow to the motor.

With a malfunctioning resistor, the blower motor runs at one fan speed or high speed only. That’s why your AC works in the back but not the front.

Clogged AC Vents

When I face the issue of the A/C and heater not working in the car, I always think of the clogged vents as one of the number one culprits.

The component allows the air to flow through into the vehicle, and I can adjust the direction of the airflow or stop the blowing by closing it.

When the vents get clogged by dust, it can cause cooling issues, such as AC barely blowing air into the car.

Defective Air Compressor

The refrigerant and compressor cooperation makes up the air conditioning system. Without the proper function of the compressor, the circulation will not be done correctly.

Lack of constant usage is one of the common reasons for a bad compressor. It usually happens when I leave the system unused for the whole winter and restart it in the summer.

The system can get shocked and damaged; thus, A/C won’t turn on in the car.

Bad Cooling Fan

The cooling fan and condenser also work in synergy. The condenser can turn the high-pressure gas into a liquid with the fan’s proper cooling.

Once the AC fan in the car is not working, it will badly influence the condenser. You may experience some sort of HVAC system malfunction.

Failed Blend Door Motors Or Actuators

They are small motors that complement the sensors of the climate control system to adjust the vent door and mix cold and hot air to produce the air of the desired temperature.

There are two HVAC actuators in the car: on the driver’s side and the passenger’s side. If the former is malfunctioning, only the rear AC works but not the front.

How To Fix?

rear ac works but not front

Seal The Refrigerant Leaks

To clear the problem of heat and AC not working in the car, I had to determine there’s no leakage in the system.

Once I detected the refrigerant leaks into the hose, I sealed it with a qualified sealant. You don’t need to spend much to find a good one and cover the leak yourself.

If you’re unsure how to do it, contact an AC repair professional for help. The sealant and labor costs usually won’t be too expensive.

Clean The AC Air Vents

If your A/C is not blowing strongly in the car, you may have clogged vents, and cleaning it may help solve the issue. Inspect its condition for any dirt build-up.

Here is how I cleaned it: 

  • Mix the detergent with water in a bowl
  • Use a foam paint brush to clean the vents. Make sure no water enters inside the detail.
  • Take a dry towel to wipe it 
  • Turn on the system to see if the problem of the AC not blowing air from vents is gone.

Replace The Compressor

You can prevent the compressor from further damage by turning the AC on full blast for 15 minutes within three weeks. Do it continuously regardless of weather and seasons.

However, when your problem of AC and heat not blowing in the car gets worse, your compressor can’t perform well, so you may need to replace it.

Seeking help from certified mechanics is highly recommended.

Repair The Cooling Fan

A malfunctioning cooling fan can result from electrical faults and fuses. You can eliminate the situation by rectifying the electrical wiring or changing the blown AC fuse.

If you have a loud fan noise when AC is in the car, it may be because an object is stuck inside.

However, if there’s something wrong with the cooling fan itself, making it unable to work, you need a replacement to avoid a bigger problem in the future.


Why Is Only One Side Of The Car’s AC Working?

People usually think of a blocked vent in this case. However, it’s more likely because of the low level of refrigerant.

When it happens, the conditioning system only regulates the temperature circulation from one end of the dashboard to the other. Thus, the AC in the car is not blowing on one side.

How Much Does It Cost To Fix This Problem?

The average cost to fix the front AC fan not working in the car falls between $100 and $900.

The price can be different depending on your car’s make and model and what component you should replace. In some cases, it may even cost from $1000 to $4,000.

The Bottom Lines

Above are the possible causes and corresponding solutions for the problem of the front AC not working but back is.

If you still can’t find the faulty component or have doubts about your inspection, bring your car to a repair shop as soon as possible to tackle the issue properly.

Leave a Comment