A/C Compressor
What it is
The air-conditioning compressor pressurises and circulates the refrigerant that cools the cabin. It is belt-driven and engages through an electric clutch.
What it does
It is the heart of the A/C system, moving refrigerant so the system can remove heat. A failing compressor causes warm air, loud noises, a clutch that will not engage, or a seized pulley that can stop the serpentine belt.
Symptoms of failure
- A/C blowing warm air
- Loud grinding or screeching when the A/C is on
- Clutch not engaging (no click when A/C turns on)
- Seized pulley that can throw or stop the belt
- Refrigerant leak / oily residue at the compressor
Which vehicles need it
Every car with air conditioning. Low refrigerant and lack of use accelerate seal and clutch wear.
Replacement cost
| DIY (part only) | $150–$450 |
|---|---|
| At a shop (parts + labor) | $600–$1,500 |
| Replacement interval | No set interval — replace on failure; running the A/C briefly year-round helps the seals. |
| DIY difficulty | Moderate–Hard (DIY) — the system must be evacuated and recharged by law; not fully DIY |
| Recommended brands | Denso, Sanden, Four Seasons, OEM |
Where to buy the part
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Recommended products
Tools to diagnose it
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Frequently asked questions
Why is my A/C blowing warm air?
Common causes are low refrigerant (a leak), a compressor clutch not engaging, or a failed compressor. If the compressor is also noisy or the clutch will not click on, the compressor itself is likely at fault.
Can I replace an A/C compressor myself?
You can do the mechanical swap, but the refrigerant must be recovered and recharged with proper equipment (it is illegal to vent it). Most DIYers do the R&R and have a shop evacuate and recharge.