AC stops working when hot

[JL4Runner06]

Hi everyone. Tried looking for past posts with these symptoms but didn’t find anything. We have finally been getting some warmer weather here in PA but unfortunately my ac had started to act up. When I first start the car the ac works no problem, but after a while it stops. The time it takes to stop varies, but the warmer it is outside the faster it stops. When it stops the ac light blinks and sometimes if I raise the temperature a couple degrees and turn it back on it’ll start working again but not always. Any suggestions?

 

[Ralph Blake]

Could be low pressure because it’s low on Freon when it builds up it starts then as pressure drops it shuts off.

 

[Drcoffee]

My first guess is: the head unit is sending power but the relay isnt working. Replace the relay. Its got a burned contact and fails as it heats up. Its not the ambient temp thats causing the failure, but the heat caused by the closed contact. Or the head unit itself is malfunctioning.


Second option: low refrigerant charge / leak

Third: worn clutch on the compressor.

 

[earthrealm]

My first guess is: the head unit is sending power but the relay isnt working. Replace the relay. Its got a burned contact and fails as it heats up. Its not the ambient temp thats causing the failure, but the heat caused by the closed contact. Or the head unit itself is malfunctioning.


Second option: low refrigerant charge / leak

Third: worn clutch on the compressor.

Second option: low refrigerant charge / leak

Third: worn clutch on the compressor

4th: overfilled refrigrant

 

[toyo]

The HVAC system has its own diagnostic system. See attached.

 

[alia176]

The HVAC system has its own diagnostic system. See attached.

This is where everyone should start before asking for help, because lots of ideas simply create confusion and drain the wallet.