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?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. AC blows warm air, refrigerant was recharged.

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: My car is making a noise from around the alternator area,but when the serpentine belt is taking off the sound stops. 2003 Ford Mustang

Hi there - good plan for diagnosis, isolate the motion that is causing the symptom! The noise could be an alternator bearing, or the serpentine belt idler or tensioner pulley bearing. These make noise that is proportional with engine speed...

Q: Coolant is bubbling

Hi. Your concern sounds very similar to an event where the system cooling fan may not be working properly. If the air conditioning is cooler as the vehicle is moving, but warm when stopped, this tells me air flow is...

Q: Ck. eng. lt. on Had it checked. replaced fuel filler cap. worked ok for a while. now lt. back on

Hi there. Typically when a check engine light is illuminated, and a repair is made, the code needs to be cleared by a professional mechanic. This could be the reason why the light periodically comes on. However, it's also possible...

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...
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...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...