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: My van is misfiring. Can I drive 400 miles before changing them? I'm traveling home now

Hi and thanks for contacting YourMechanic. If the Check Engine Light says that your vehicle has a misfire, then you will need to check the spark plugs and wires. I suggest replacing the spark plugs if they have hot spots,...

Q: How much A/C refrigerant does a 2007 Lexus GS350 takes

The system hold 1.0 lbs of refrigerant for the air conditioner. Remember if you lost oil out of leak then the system oil total is 4.5 oz. You may need to add a couple oz of oil also. The system...

Q: My car is revving up but doesn't seem to be shifting. If my gas is low, could this be the cause

This may be caused by a number of reasons. The hesitation feeling you are experiencing is very commonly known to be related to what is called a mass air flow sensor which regulates the air intake as the the fuel...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...
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...