Car AC Compressor Not Turning On

One of the most important parts of a car is the AC, and the ability to create a very cool atmosphere for its passengers. The driving experience is usually watered down when the AC doesn’t work.

There are times that you turn the AC of your car on, and instead of you to get cool, almost fresh air, what comes out is pretty hot tight air. Now try to picture this happening in the middle of a very hot day.

Just thinking about it must be frustrating, right? In this article, you’d find out all the reasons why your car’s AC isn’t turning on, and how to fix it.

What is an AC Compressor?

An AC Compressor is the part of your vehicle responsible for providing air to your car to cool the atmosphere of the car. It moves the refrigerant or air gas between the condenser coils and the evaporator.

The AC Compressor makes sure that the refrigerant transforms into gas, or liquid, depending on the need at a particular time.

During this process, all the heat and humidity in the air stored in your car is transformed into the cold air that gives your car proper air conditioning.

If the compressor doesn’t work, then your car will not generate AC when you turn it on. Instead, you get bombarded with hot air and a hot day becomes hotter.

In other words, just like the lungs make breathing work, AC Compressor makes the air conditioner work. If the lungs of a person get destroyed, breathing becomes a thing of the past.

Why is my Car AC Compressor not Turning On?

There are various reasons why the car AC compressor is not turning on , and there are solutions for each of them. For every problem with your compressor, there’s a fix that will make it work.

Here are some of the reasons why your AC Compressor might not turn on:

1. The AC Pressure Sensor Switch is Faulty

One of the popular causes, of why your AC Compressor might not turn on, is the damage to your sensor switch.

Naturally, when you turn the switch of your AC on, it switches your HVAC system from hot to cold, and if this doesn’t happen, then it probably means that your HVAC system is stuck in between hot and cold, and needs to be fixed.

2. Lack of Refrigerant in your Air Conditioning System

When you switch on a water tap, and water doesn’t come out, the first thing you think about is that the tank is already empty, and water needs to be pumped.

In the same way, if cold air doesn’t come out of your AC Compressor after turning it on, it most likely means you have run out of refrigerant, or the refrigerant in your system isn’t enough to cool your vehicle.

3. Damaged Compressor

Your AC compressor itself might have gone bad if it doesn’t come in. Perhaps the compressor is dead, damaged, or faulty due to something broken or loose in between.

As said earlier, if your compressor doesn’t work, you won’t get AC powered to the atmosphere of your vehicle. This can be another reason for your compressor not turning on.

4. Problem with Fuse or Capacitors

Sometimes, it could be an electrical problem, that is, a wiring problem. The AC Compressor might be pretty much alive and efficient, but it isn’t coming on due to a broken wire.

When a wire isn’t properly affixed to the proper fuse or capacitors, the AC Compressor of your car won’t work, and it will be an electronic issue.

5. Wrong Wiring

It could also be that the wiring itself is just completely wrong, and needs to be organized.

When there is enough refrigerant in your vehicle, and you have also confirmed that the AC Compressor is in the right condition, the wiring might be another famous reason why your compressor won’t turn on. 

How to Fix Car AC Compressor Not Turning On

Here are corresponding solutions to issues that might cause your car AC Compressor not turning on and what you should do.

  • For a faulty AC pressure sensor switch; you replace the sensor switch with a new one, as a damaged sensor switch won’t do you any good. It will simply remain stuck between hot and cold until you are ready to change the switch.
  • If the issue is that you have run out of refrigerant, you need to re-fill the AC of your vehicle, and after re-filling, it will do you a world of good to observe the gauges to know that you are at the appropriate amount of PSI.
  • For a damaged compressor, the only thing that can be done is to replace the compressor. Get a new one. You really cannot properly repair an AC Compressor, so it is usually advisable to get a new compressor.
  • When the problem is with your fuse or capacitor, examine the capacitor and fuses, replace the ones that need to be replaced and get the wiring around the fuse back on track.
  • For bad wiring, examine the wiring compartment and properly tighten the wires and connections around your AC Compressor. Wrong wiring can lead to more disasters than just your AC Compressor not turning on.

How Do I Get my AC Compressor to Kick On?

To kick on your AC Compressor, you have to locate the front side of the compressor, then you will find the single wire connector around the compressor. Unplug the wire connector and attach it to an already prepared jumper wire.

Once you do that, take the other end of the jumper wire and connect it to the positive terminal of your car battery, or any car battery in use at that moment.

This way, you can kick on the AC Compressor by yourself. It isn’t a difficult process.

Is There a Reset Button on AC Compressor?

Yes, there is a reset button for a car’s AC Compressor. However, depending on the type of AC Compressor you are dealing with, the reset button can either be outside the compressor or inside the compressor itself, just behind the service panel.

Make sure that the power from your vehicle is already disconnected before you try to locate the reset button for the resetting of your AC Compressor.

At the end of the day, if the issue with your AC Compressor is due to any of the five reasons explained above, no matter how many times you reset it, the AC Compressor still won’t turn on, until you fix the AC problem.

How Do I Know if My AC Compressor is Not working?

Here are some of the ways to know a bad AC Compressor:

  • Reduced airflow.
  • Screeching noises coming out of your AC.
  • Hot air coming out of your AC system instead of cool air.
  • It takes too long and it becomes strenuous for your AC to start in the first place.
  • If there are rising issues from your circuit breaker.


There are many reasons why your car’s AC Compressor has stopped working. The key to finding a solution is finding the cause.

It is very rare for the AC Compressor to stop working suddenly. It must have been giving symptoms of inefficiency, perhaps indicated by reduced airflow or noises. It helps a lot to be more attentive to issues around your car.