If the compressor clutch engages and turns the compressor, but the A/C still does not blow cold air, the system is probably low on refrigerant and needs to be recharged.
If your AC is running but not cooling, it could be due to a dirty air filter, incorrect thermostat settings, a malfunctioning thermostat, a refrigerant leak, dirty condenser coils, blocked vents or ducts, a faulty compressor, frozen evaporator coils, or electrical issues.
Check your electrical panel for a tripped breaker or blown fuse. Reset the breaker if necessary. The capacitor helps start the compressor. If it's faulty, the compressor won't run. Look for signs of bulging or leaking. If you suspect a bad capacitor, it may need to be replaced.
Either it isn't getting proper voltage, the capacitor is sized incorrectly or wired wrong, or the compressor is mechanically locked up/has a motor winding issue.
One key indicator that your compressor is failing is when your system blows warm air instead of cold air, even if the condenser seems to be running well. This is evidence that the compressor has lost its cooling power, and therefore unable to pump the refrigerant through the system.
Most air conditioners come with a reset button attached to the compressor unit. Typically, it is a red button and is very visible to an onlooker. To reset your air conditioner, all you have to do is press the button, and you won't have to worry about all the heavy lifting.
Make sure the outside unit is turned on (there's probably a switch near the unit). If the outside unit has a separate circuit breaker, check your circuit box and make sure it hasn't been tripped. A more serious issue if the outside air conditioning unit's not working is a broken compressor, capacitor or fan.
The location of the reset button on your compressor can vary depending on the model and manufacturer. Typically, it is located on the motor or near the motor housing. Look for a small red or black button that is often labeled “reset.”
On average, AC compressor costs range from $800 to $2,300, with most folks paying $1,200 for a new one. However, your price will vary depending on factors like the size and brand of your compressor. Before you schedule your replacement, read on to learn about all AC compressor cost factors.
Over time, the fan motor on the outside AC unit can wear out, causing the outdoor unit to stop working even when the inside AC unit is on. The fan motor can last 10 to 20 years with proper maintenance, like annual inspections and regular AC unit cleanings, but it will wear down faster without regular maintenance.
Faulty Air Conditioner Capacitor
The starter relay moves that power to the compressor from the capacitors. If your compressor isn't working but the fan is,you may have a faulty capacitor. This is a common and fairly simple problem, but it's important to leave this repair to a qualified and experienced HVAC technician.
Overheating is a common cause of compressor failure, and there are many factors at play. If direct sunlight falls on your outdoor unit and there is inadequate ventilation around it, it makes your unit's compressor overheated. High voltages can also damage the motor causing the compressor to overheat.
What's Preventing the A/C Compressor from Engaging? One of the reasons why compressors do not engage is because of a low pressure lockout, a poor ground, a bad clutch coil, an opening in the wire to the clutch coil, or simply a blown fuse.
Check for the simplest remedies first, such as whether the power cable is still connected and the switches are all in the right position. You may also need to check and replace fuses, reset breakers, check the pressure switch, and activate a reset switch to get the machine back into power mode.
Set your multimeter to continuity and place the pins on the contacts. Setting the dial on your multimeter to continuity will test if current is properly running through your compressor clutch. Replace the coil if the reading is below 3 ohms or above 5 ohms.
In AC systems, the air conditioner reset button is on the outside unit's lower edge, typically close to the ground. Some models have the reset button located behind the service panel, which may require tools to remove. Reset buttons are usually red or yellow with a clear “reset” label.
From a blown fuse to issues in the engine compartment, several electrical components could prevent your compressor from turning on. Always ensure that your compressor has power. If it doesn't, the problem might lie within the power supply, wiring, or a fused connection needing replacement.
You'll want to have the unit examined for signs of a blown fuse, tripped circuit breaker, broken thermostat, or dirty air filters. Dirty or clogged filters commonly make AC compressors stop working. When it comes to operating your cooling system properly, be realistic with the temperature setting on your thermostat.
A sure sign of a bad AC capacitor is a humming sound from within the access panel. Any humming noises indicate a problem with the air conditioning system or the components of the AC unit. Try turning the power on and off again to see if it was a one-time issue with the motor or a recurring problem.
Look for a RESET Button.
Some systems have a RESET switch on the outside unit. You can push this and see if it helps. If your unit does not, you can turn off the system at the thermostat, wait 5 minutes, and try again.
Some of the obvious signs of a bad compressor include loud noises coming from the unit, water leaks around it, and reduced airflow. To fix the problem, some choose to replace the compressor, while some prefer to replace the entire unit.
Generally speaking, to have a shop properly change an AC compressor and related components, flush, and re-fill the AC system will run between $750 – 1500.00. Depending on the model and cost of the parts in general, this cost could be even higher.