Skip the auto shop - Our mechanics make house calls

Q: AC blows warm air, refrigerant was recharged.

asked by on

refrigerant was recharged. Still blows hot or warm air.

My car has 167000 miles.
My car has an automatic transmission.

Hi there. When the refrigerant was recharged, was the system evacuated and a vacuum test performed to ensure there are no leaks or moisture in the system? It sounds like the AC compressor may not be engaging. A blown fuse, relay, failed clutch, failed compressor, wire harness failure, or module could be the cause.

Attach a known good set of AC pressure gauges and monitor the high and low side pressures. If the pressures are about the same on both sides, then the compressor’s internal check valve has failed and is preventing the compressor from performing.

Make sure the AC indicator lights up when you turn on the AC. If it flashes, this is an indicator that the compressor is not coming on when commanded. The clutch, a relay, a fuse, or wire harness could be at fault. Check for blown fuses and relays that are not responsive when the AC is turned on and replace as necessary.

The AC clutch is an electromagnetic device that locks the ac pulley to the compressor to drive the compressor. If the clutch has failed or any of the electrical components that provide it power fail, then the clutch will not engage.

A quick voltage and ground check at the clutch and resistance check of the clutch will reveal any faults that may be present. If you would like to have this issue taken care of, a certified professional from YourMechanic can inspect your AC system and advise you on the appropriate repairs.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Audi A4 engine not running smooth

The first thing would be to check the throttle body to see if it is really black from oil? If it is then you may have leaking oil seals in the turbo causing you to burn oil. This may also...

Q: air condtioner stopped working

Hey there. If replacing the resistor did not repair it, then it was not the cause of the fault. Straight wiring power to the blower motor indicates that the blower motor is capable of working. Some other AC component has...

Q: Brand new battery car won't start - 2000 Chrysler Concorde

Hi and thank you for contacting YourMechanic. It sounds like there is a ground to chassis problem that is draining your battery. Check your negative battery cable for corrosion and make sure that the connection points are secure and clean....

Related articles

What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the...
P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...