8 Reasons Why Your Car AC Compressor Won’t Turn On (and Solutions)
- Low Refrigerant in the AC System. This is by far the most common issue as to why your AC is not working. ...
- A Faulty Car AC Pressure Sensor Switch. ...
- Relay or Fuse Problem. ...
- Compressor is Dead. ...
- It’s Not Getting Power. ...
- Wiring Issue. ...
- Compressor Clutch Isn’t Engaging. ...
- Rusted Clutch Plate. ...
Why my car AC is not working?
Why did my car AC suddenly stop working? There are several things that can cause electrical problems for your car’s air conditioning. These can include failed switches, a blown fuse, a problem with the control module or something else.
How to replace AC compressor in your car?
Part 2 of 2: Remove the compressor
- Locate the serpentine belt tensioner. If you have a difficult time finding the tensioner, consult the belt routing diagram. ...
- Rotate the tensioner. Use a socket or wrench to slide the automatic tensioner away from the belt. ...
- Remove the belt from the pulleys. ...
- Disconnect the electrical connectors from the compressor. ...
What can I do if my AC compressor is not working?
There are various reasons behind AC compressor not working:
- Excess refrigerant flow : The compressor's job is to compress the low pressure cool refrigerant into high pressure hot gas. ...
- Lack of lubrication: A compressor needs lubrication for proper operations. ...
- Poor heat dissipation: The compressor compresses the cool low pressure gas into high pressure hot gas. ...
What are the symptoms of a bad AC compressor?
What Are the Signs and Symptoms of a Bad A/C Compressor?
- A Lack of Hot Air Being Released Outside. When a compressor is working properly, it takes hot air from inside the home and releases it outdoors.
- Loud or Strange Noises From the Unit. Have someone in your home turn on the air conditioning while you stand outside beside the unit. ...
- Failure of the Compressor to Turn On. ...
- Circuit Breaker Tripping. ...
How do I get my AC compressor to kick on?
At the compressor's front side, unplug the single wire connector, take a jumper wire and attach it to the wire that you just disconnected from the compressor. Connect the other end of the jumper's wire to the positive terminal of the car battery. This will enable the compressor to start manually.
Why doesn't my AC clutch engage?
If the clutch doesn't engage, the problem could be a blown fuse, an open in the wire to the clutch coil, a bad clutch coil, a poor ground, or a low pressure lockout. In some vehicles the compressor clutch relay is turned on and off by the low pressure switch and the evaporator temperature sensor.
How do I engage my car AC compressor?
0:031:55Engage AC Compressor Clutch with a Paperclip on Relay - YouTubeYouTubeStart of suggested clipEnd of suggested clipSo you could see that it has that open and closed indicator on that diagram. And my jumpers are 30MoreSo you could see that it has that open and closed indicator on that diagram. And my jumpers are 30 and 87 and for most cars it will be 30 and 87. And the inscription usually is on the pins.
How do I know if my AC clutch relay is bad?
Common signs include inconsistent cooling, not hearing a click from the compressor turning on, and no cold air.
AC Compressor Problems & Solutions
There’s a lot that could go wrong with the air conditioning system, but by correctly identifying the source of the problem, we can narrow down the possible causes.
Electrical Problem
As odd as it may sound, an electrical problem is a best-case scenario. The AC compressor problems are generally expensive to repair, while electrical issues are trivial in comparison – a blown fuse or relay, or a loose power plug.
Compressor or Clutch Failure
The compressor pulley is spinning at all times, but once the clutch engages, the pulley will begin transferring power to the compressor. Start the engine and turn on the AC to see if the pulley is spinning together with the clutch disc.
FAQs
The AC compressor can be jump-started by shorting its control relay. However, you also have to jump-start the AC fan and the condenser to make the whole system work. If the problem is in the relay, it’s much easier and safer to just replace it, than to manually start the AC.
Summary
The problems with the AC compressor not engaging can be traced to the clutch compressor and an electrical problem that is preventing it from engaging.
Why is my AC compressor not turning on?
How to diagnose my car AC compressor is not turning on. When the compressor doesn’t turn on at all, it can mean a couple different things. You are either too low on freon, you have a power/ground issue meaning the compressor isn’t receiving the signal to turn on, or the clutch itself is bad. You will need a set of AC pressure gauges to check ...
How to check if a compressor has enough freon?
First thing is to start with checking the freon pressure. Static pressure will give you a good idea if the system has enough freon to tell the compressor to turn on. Hook up your gauges and record the static pressure. Depending on the ambient temperature (air temperature of outside atmosphere), the static pressure of a full system should be ...
Can you recharge an AC system if static pressure is within spec?
If the static pressure readings are within spec, you can evacuate and recharge the system anyway (it never hurts to service your AC system) just to positively eliminate a freon level issue. But likely, you will need to dive into electrical diagnosis from here. Follow the link below to get a good electrical flow chart.
What happens if your AC compressor is faulty?
In general, the most common problem with the refrigerant is that the liquid instead of fuel comes into the inlet of the compressor . In these situations, the compressor might still work, but your air conditioning system would not cool the air.
What happens when the refrigerant is still locating in the compressor?
When the refrigerant is still locating in a compressor, it is often seen as the beginning part of an air conditioning cycle. If an AC compressor could not turn on, this process could not begin.
How does an air conditioner compressor work?
In an air conditioning system, this part operates by compressing gaseous, low-pressure, and cool refrigerant till it becomes hotter and gets a much higher amount of pressure . After that, it squeezes the gaseous refrigerant into a condenser. When the refrigerant is still locating in a compressor, it is often seen as the beginning part ...
How to troubleshoot capacitors?
The only way that you would troubleshoot the capacitors is to replace it and test the unit. Thus, this is a common task when the compressor in your AC system does not turn on. Start relay: Just like the capacitors, an HVAC technician might try to replace the start relays, which is probably the sure-fire way to know if it is working correctly or not.
What is a car compressor?
What is a Car’s AC Compressor? In most car models these days, an air conditioner could not work correctly without an operating compressor. In many standard residential AC systems, a compressor is often placed in the outdoor area. As its name suggests, the main function of a compressor is definitely compression.
Can a blown fuse cause a tripped breaker?
In some cases, a fuse would be blown or a breaker would be tripped. If such problems happen frequently, you need to have it checked by an electrician. In fact, it is not usual for the breakers and the fuses to experience persistent issues. Constant starts and stops could do a lot of damage to the compressor as well as on an AC system as a whole.
Can an AC compressor fail?
An AC compressor is made with a lot of different parts, and any of them could fail and lead to an issue. Therefore, a technician who comes to your home would take into consideration the following possibilities, then try to rule out each of these:
How to check if AC compressor is working?
Check to see if the air conditioning compressor is still working if you can’t find any obvious issues. Leave your car's hood open and turn on the engine. Turn on your AC even if it isn't working, and go to the front of your car to listen to the compressor. You should hear the AC compressor working or attempting to work. If it's silent, you may have a fuse that has burnt out or disconnected. The wiring leading to and from the compressor could also be damaged or worn away. Have a mechanic check over the electrical system for the compressor, and this could put your AC back in business.
What to do if your car AC won't work?
Get out of the car and look all around your front grill and bumper. Pieces of debris and mud can hinder airflow under the hood of the car, which will prevent your AC from working. If you see anything that could be restricting air flow, get it out of there and try the AC again.
How does a car's freon work?
The Freon goes through expansion valves where the gas/liquid combination expands or contracts based on how much air conditioning is needed. The cold Freon then goes through an evaporating core, where the cold air it creates is released into the car.
What to do when your car's air conditioner won't work?
When your air conditioner won’t work, put on your DIY hat, take a look at the system, and try to figure out what’s wrong. This will save you time and money with a mechanic, and could make it possible for you to fix ...
Why is my AC silent?
If it's silent, you may have a fuse that has burnt out or disconnected. The wiring leading to and from the compressor could also be damaged or worn away. Have a mechanic check over the electrical system for the compressor, and this could put your AC back in business.
Can you troubleshoot an air conditioner?
It’s impossible to troubleshoot problems with your air conditioning if you don’t know much about how it works. Air conditioning is actually less complex than you may think. The system is made up of a compressor that pumps Freon (a gas and liquid combination) through the entire system. The Freon goes through expansion valves where ...
Why won't my air conditioner cool?
The most common issue is that the refrigerant is liquid instead of gas when it gets to the compressor inlet. Under these circumstances, the compressor may still run, but the air conditioner won’t cool the air. Fortunately, replacing the broken valve or valves usually resolves the problem. Terminal Connections – The tech will also check ...
What to do if your air conditioner compressor is dead?
If the compressor in your air conditioner is deemed to be completely dead, you will probably have two options. You can either replace the compressor, or you can replace the entire air conditioner. The main determining factor is the cost to replace the compressor. If it’s less than 50 percent of the cost of buying a whole new unit, it’s probably the best way to go. If it costs more than that, though, buying a new air conditioner is probably the most practical choice.
How to troubleshoot a capacitor?
The only way to troubleshoot a capacitor is by replacing it and testing the unit, so this is commonly done when an AC compressor won’t turn on. Start Relays – As with the capacitor, the HVAC technician may try replacing the start relay, which is the only surefire way to determine whether it’s working right or not.
How does a compressor work?
In an air conditioner, it works by compressing cool, low-pressure, gaseous refrigerant until it is hotter and has achieved a much higher pressure. From there, the gaseous refrigerant is squeezed into the condenser.
Can a compressor cause a problem?
Compressors have many components, and any one of them can fail and cause a problem. The tech who arrives at your home will consider the following possibilities and attempt to rule out each one: Capacitors – In many cases, compressor problems are caused by faulty or broken capacitors.
Can you use a multimeter to check a compressor?
If so, you can use it to check and see whether the right voltage is going into the compressor. Even if you’re able to determine that, you will almost certainly need to have an HVAC technician take it from there.
Can compressors be repaired?
This may sound like dire news, and it possibly is , but compressors can often be repaired. Before jumping to any conclusions, you should do a little troubleshooting to try and pinpoint the source of the problem. Keep in mind that there’s only so much that an everyday homeowner can do in this regard.
3. Check For Cabin AC Air Filter
Secondly, you should check the cabin AC air filter for fixing the car AC compressor not turning ON. Sometimes AC turns ON but due to a clogged air filter, air can not bypass the air filter and you think that AC is OFF.
4. Check For The Leaky Evaporator
Troubleshooting the evaporator is difficult. If a leak occurs in the evaporator then there is a maximum chance that the car AC compressor will not turn ON. The symptom of the leaky evaporator is oily mist on the inside of the windshield through the defroster duck.
5. Check For Thermister
Thermister is a temperature-sensing device fitted in the evaporator. It is an essential component in the car’s modern AC system. It tells the AC control module about the temperature of the cabin. A faulty thermister will not provide the module about cabin temperature and as a result, the car AC compressor clutch does not engage.
6. Look For The Compressor Clutch
The first thing you should look into to fix a car AC under the hood is the compressor clutch. Does it sound click when the air conditioning is turned ON?
7. Check The AC Belt
The second thing you should check is to Inspect the AC belt tensioner. Sometimes the AC belt is loose, which cannot rotate the compressor pulley, as a result, the car AC compressor clutch will not engage. Therefore, check with fingers pushing down on the belt to look for belt tightness.
8. Check For AC Fuse And Relay
Fuse and relay have a huge impact on the car AC compressor’s clutch not engaging. Check for AC fuse especially looseness and blown fuse and also check for relay such as a corroded relay.
9. Check For AC Wiring
If everything is OK and still the car AC compressor does not get power, there might be a wiring issue. Look for the AC compressor connector, it can get broken, corroded or sometimes the compressor ground connection gets corroded, as a result, the car AC compressor clutch will not engage.