2010 Lonestar AC

[Smooth]

Looking for thoughts and/or Ideas been down this road with this truck a couple times.

AC not Blowing Cold
Freon Is Good
Compressor working and cycling as it should. Lines or cold sweating down etc.
Changed the Thermistors with New End Caps etc. And have monitored them in DLB and appear to be working normal.
I have Diamond Logic , No AC Faults or Body Controller Faults
All Blend Doors are working Normally with no issues in cab and the bunk. Air is not Cold in either

I have monitored the Temp on the Evaporator it went down to 37 once and then went back up to around 50 with in 5 Minutes. I have reset the Body Controller a couple times and the system will begin to cool. Example the Temp on outlet of Evap will start at 75 outside Air temp dropped to around 50 and stop there. If continue to run the compressor cycles normally while monitoring High and Low pressures which are normal. But the temp of the air never gets cold.

We took the Body Control Module from a sister truck to test and same results as above.

Ambient Air Temp sensor is working normally as well monitored it on DLB

Any ideas appreciated

[Nilao]

My compressor never did cycle often. If it is cycling you have a pressure problem. If your freon is okay (proper weight in the system) then it could be your expansion valves are stuck closed and the system is cycling for low pressure on the low side.

Just what I think off the top of my head.

[david24]

(05-12-2023 )Smooth Wrote:  Looking for thoughts and/or Ideas been down this road with this truck a couple times.

AC not Blowing Cold
Freon Is Good
Compressor working and cycling as it should. Lines or cold sweating down etc.
Changed the Thermistors with New End Caps etc. And have monitored them in DLB and appear to be working normal.
I have Diamond Logic , No AC Faults or Body Controller Faults
All Blend Doors are working Normally with no issues in cab and the bunk. Air is not Cold in either

I have monitored the Temp on the Evaporator it went down to 37 once and then went back up to around 50 with in 5 Minutes. I have reset the Body Controller a couple times and the system will begin to cool. Example the Temp on outlet of Evap will start at 75 outside Air temp dropped to around 50 and stop there. If continue to run the compressor cycles normally while monitoring High and Low pressures which are normal. But the temp of the air never gets cold.

We took the Body Control Module from a sister truck to test and same results as above.

Ambient Air Temp sensor is working normally as well monitored it on DLB

Any ideas appreciated

I put a cutoff valve on mine. It’s been blowing well ever since. Hopefully it continues. Only inconvenience is when it’s cold in the mornings and I open the valve for the heat and it gets hotter in the afternoon and I have to pull over to close it again so that the air works

[DVT873]

Look closely at the enclosure. Hard to see all sides. They can crack and exhaust has been known to melt holes in them. Lets ambient air in where the evaporator core is. I think there are some posts on this site about that.