There is nothing to worry about if the AC compressor cycles on & off. It’s because the AC system works in this way to cool down the air. But what if the AC compressor cycles on and off every 5 seconds or rapidly?
If your car ac compressor cycles on and off rapidly, we bet the HVAC system of your car is going through some problems. And this troubleshooting guide will help you figure out what causes the ac compressor to short cycle. So, stay in tune with us till the end.
Table of Contents
- Is It Normal For AC Compressor To Cycle On And Off
- AC Compressor Cycles On And Off Every 5 Seconds [5 Easy Solutions]
- 01. Low On Refrigerant
- 02. AC Components Freezing Up
- 03. Evaporator Or Condenser Get Clogged
- 04. Refrigerant Level Is A Little Too High
- 05. Forget To Purge The System
Is It Normal For AC Compressor To Cycle On And Off
Yes, it’s normal for your car AC compressor to cycle on and off. It’s the process of how an ac compressor works and cools down the cabin. Every time the air of your car cabin gets hotter, the compressor cycles to cool down until it reaches the temperature you set.
Generally, an AC compressor cycles on for between 4-10 seconds and off for 15-20 seconds. However, the time of cycle on and off may swing drastically by different variables like the cabin temperature, AC’s cooling capacity, the season, humidity, and engine RPM.
Besides, outside temperature, vehicle speed, amount of refrigerant, fan speed, and how well insulated your car is are other factors that affect the AC compressor’s duty cycle.
For example, if you drive your car on a cold day with low fan speed, the compressor will remain off most of the time and cycle on occasionally for a few seconds.
On the other hand, the AC compressor will run continuously if you sit in traffic on a very hot day with the maximum fan speed. And guess what, it’s normal because the AC system of your car fails to work at its best at idle.
In a nutshell, it’s normal for an AC compressor to cycle on and off and there is no definite cycle time for an AC compressor.
AC Compressor Cycles On And Off Every 5 Seconds [5 Easy Solutions]
Ac compressor cycles on and off rapidly or every 5 seconds due to low refrigerant level. Therefore, other factors like frozen-up AC components, dirty evaporator or condenser, high level of refrigerant, and failure to purge the system properly are responsible for AC compressor short cycling.
Below, we will describe each of the culprits and show you how to deal with the specific problems. So, keep scrolling.
Note: You can also read why is my car’s AC Compressor not turning off.
01. Low On Refrigerant
Low on refrigerant is the main culprit that causes your ac compressor to cycle on and off repeatedly. The refrigerant is a coolant that spreads through the AC system and absorbs the hot air of your car cabinet and cools down the air.
If there is a leak, the level of refrigerant will be getting low. Consequently, the ac compressor goes to the off position because of the low pressure. And when the compressor is in the off position, the pressure will rise again and turn the compressor on what causes an ac compressor to short cycle.
Because of the short cycle, the parts of your AC will wear & tear faster and cause the compressor to get defective fully.
It would be risky to deal with the leaking refrigerant. So, we recommend you call a certified HVAC guy for help.
02. AC Components Freezing Up
When the AC components start to freeze, it will cause inadequate cooling and the ac compressor to cycle on & off. This can cause the AC compressor to fail since it’s overworking.
Generally, a clogged cabin air filter that restricts airflow is the main culprit responsible for freezing up the AC components. The easiest way to check for freezing issues is to look for large puddles of water underneath your vehicle.
First off, check the air filter for blockage. If the air filter gets clogged by dirt and debris, you need to replace it. Then, check the refrigerant level and refill if needed.
Now, use an AC gauge to check the pressure. Ensure the system is not overcharged or undercharged. Alternatively, you can take help from a pro HVAC guy to fix this problem.
03. Evaporator Or Condenser Get Clogged
Your car ac compressor is nothing more than a heat exchanger. It will transfer no heat unless sufficient air is following through the system.
And the evaporator and the condenser are the parts responsible for allowing air to pass through the AC system.
If these components get clogged by dirt and debris, sufficient air will not flow through the system to cool down the cabinet. As a result, the compressor will cycle on and off rapidly like every 5 seconds for compensation.
The only way you can solve this issue is to clean the evaporator. You can use a can of cleaner to clean this part. If you don’t know how to clean your car evaporator, check out the following video:
Also, you should check the condenser for dirt buildups and clean them to let the compressor work properly. We recommend you check the below tutorial if you don’t know how to clean a car AC condenser:
04. Refrigerant Level Is A Little Too High
Yes, it’s true that a compressor can cycle on and off every 5 seconds or often if there is a little high level of refrigerant in the system.
When you add too much refrigerant, it will flood the condenser and reduce its capacity to flow sufficient air. Consequently, it causes your ac compressor to short cycle.
What we suggest you do is- remove all the refrigerant from the system. Then, refill the system with fresh refrigerant according to the manufacturer’s specifications. Either way, you can hire a professional to fill the AC system with the correct level of refrigerant.
05. Forget To Purge The System
You already know that a low level of refrigerant causes the ac compressor to cycle on and off. But this is not the issue we will discuss here.
Once you verify the system needs refrigerant, some owners just get a can of refrigerant and jump the gun on adding this coolant to the system.
But they miss the step of purging the air from the line which goes from the refrigerant bottle to the low side port. As a result, there will remain air in the system causing the short cycle issue.
Purging the line is not rocket science. What you need to do is- just hook the refrigerant can up to the gauge manifold. Then, set the valve on the bottle or can to the open position.
Next, unscrew the connection where the line from the can to the gas manifold meets to purge the air out of the system. Finally, charge the system with the correct level of refrigerant by opening the low side valve on the manifold.
Your car’s AC compressor will cycle on and off. And there is nothing to worry about because this is how the AC system works and cools down the air. However, if the ac compressor cycles on and off rapidly like every 5 seconds, understand there is an issue with the system.
Fortunately, we mentioned all the reasons that cause the ac compressor to cycle on & off. At the same time, we also broke down what troubleshooting steps you should take to solve the short cycling problems. So, follow our guide and get a functional AC compressor.
About John M
John contributed as a technical head at an automobile company just 2 years after his post-graduation in Automobile Engineering. He loves to lead a free life, so he left his job & started blogging. Now, he does research on every automotive problem, part & product and seeks a better solution & best products & shares his findings with his readers to help them as well as to minimize their struggle.