AC issues, mind blown…

[mherbaugh]

I have a 2000 (new body style) 2500 6.0l with 190,000 on it. 
 

The AC has always blown cold as ice. But recently it will only blow cold for the first 5 or so mins of turning the truck on then it will blow hot air. 

ive changed the relay, blend doors, control panel and low pressure switch but nothing has fixed it. Check the pressure and it is good. And when the compressor is running the gauges are ready properly. 
The compressor will kick on the first couple times but after that it won’t. 
If you jump the relay it will stay on and work fine. 
 

anyone ever had this issue before?

[CamGTP]

I'd suspect one of the pressures switches on the AC system. You'd need a scan tool to watch the pressure readings. One of the sensors could be failing after that 5 minutes thus causing the AC to stop working.

 

I believe there is a high pressure cut switch or refrigerant pressure switch on those trucks.

Edited August 27, 2021 by CamGTP

[mherbaugh]

Okay. There is a high and low pressure switch on these. I forgot to mention sometimes it will only blow hot air when you first start it up. But 90% it’s cold when you start it up

Edited August 27, 2021 by mherbaugh

[Super 8]

 

[Super 8]

Did you change the cabin air filter?