Car A/C Compressor Turns On And Off: Causes & Fixes

If you have a car that has an A/C compressor that turns on and off, it could be due to several different causes. In this article, we’ll go over some of the most common reasons why your A/C compressor might be doing this and how to fix it.

The Cooling Fan Comes On

The cooling fan comes on when you turn on your car, and the engine is cold. The fan helps cool down your engine to run at maximum efficiency. When the engine is warm, this function turns off automatically.

However, if the A/C is turned on and there’s still a noticeable lag in airflow (particularly during start-up), this might indicate that something needs to be fixed with your AC system.

No Cold Air

If you’ve got a car that won’t blow cold air, your first step should be to check the A/C system for leaks. If there are no leaks and your A/C still isn’t blowing cold, it’s time to dig deeper into what’s going on under the hood.

You can start by checking the compressor, which is usually located behind the engine or on top, depending on whether it’s a front-wheel drive or rear-wheel drive vehicle. Compressors have hoses going in and out of them, and they can be checked with an ohmmeter if you want to see if they’re working correctly (you’ll find this information online). In most cases, this will tell you if there’s an issue with how much power is being generated by your compressor—something that could cause it not to work at all or not work well enough for your liking (i.e., no cold air).

The Cooling Fan Stays On For A Long Time

The cooling fan should turn on only when the car’s air conditioning compressor is running. The fan turns off after a few minutes when the temperature in the car cools down. If your car’s cooling fan stays on for a long time after you hit “off,” it’s likely that your A/C compressor isn’t working right and needs to be replaced. This could also indicate that your vehicle has an air conditioning leak and is losing refrigerant.

Check The Coolant Level

Regarding the cooling system, there are several ways to check for leaks. First, check the coolant level in your vehicle’s overflow reservoir. If it’s low or empty and you’re seeing evidence of overheating (flames under the hood), you might have a leaky radiator or water pump. Next, check the coolant level in the radiator itself by removing its cap to see if there’s liquid inside. Next up: check out your expansion tank—this is where excess pressure from overfilled radiator tanks goes when they’re opened and closed repeatedly during routine maintenance, like topping off with distilled water or replacing old antifreeze with new stuff. Finally, remove and inspect your water pump (it should be located near or on top of your engine block) and make sure there are no signs of leakage around any seals or gaskets—if there are any obvious signs that something went awry here.

Check For Refrigerant Leaks

If your car’s air conditioner is not producing cold air, ensure the blower works properly by turning it on and off. If it doesn’t work, check your fuses and fusible links first. If you have a new fuse or link, try installing them one at a time to locate which one is causing the problem.

Check For Clogs Or Obstructions In The A/C System

If you are experiencing an issue with the A/C compressor turning on and off, your system may have a clog or obstruction. If this is the case, you will want to ensure that a professional mechanic clears the problem before you can use your air conditioner again.


Hopefully, this article has helped you understand what your car’s A/C compressor is and why it turns on and off. If you are experiencing any of these issues in your car, it’s time to get it checked out by a professional.