A failing AC compressor rarely gives up without warning. The compressor pressurizes refrigerant and pushes it through the system, so a problem there can leave the car blowing warm air even when refrigerant is present.
Early Warning Signs
- Clicking, grinding, or squealing noises when the AC is switched on
- Air that is cooler than outside but never genuinely cold
- The AC cycling on and off every few seconds
- Visible oily residue near AC lines or compressor fittings
- A compressor clutch that no longer engages when the AC is turned on