The engine has been amazing. This truck has towed our 20 foot fifth wheel all over North America for the last 7 years. Its not the old mechanical 4BT but the newer common rail ISB170. Lots of power and 22 MPG towing.
https://youtu.be/qe6sHb1FDlA

Well, I'm beat,I admit defeat. Today I converted it all to manual. Basically just a pressure sw and core temp switch on the ground side of the stock compressor relay and the stock keyed / fused power on the positive side. I ran it this way for years in the past but was determined to make the stock s...

That was easy, was able to just go into the body control module and turn off ATC and the sensor error went away. I have pinned all the harnesses to be sure they are getting signals where they need to go, can see the BCM request that the ECU turn on the AC relay but it wont. I confirmed that the AC r...

Looks like this may be the or a problem to look at tomorrow. The infrared temperature sensor is located in the overhead console and consists of an infrared transducer concealed behind a clear lens (2) in a molded plastic housing with an integral wire connector receptacle (1) and mounting tab (3). Th...

Yes, just fabricated a mount for the Dakota compressor. Replicated the CPS on the front of the Cummins. The Dakota ECU is just a driver for the other modules and is not tied to the Cummins ECU. The Dakota ECU is "Happy" with no DTC's.

Just found code B1035 INFRARED TEMPERATURE SENSOR HIGH in the overhead module. I did a search for info and get very little on what it is and location.
Any idea what this is and where I find it?

Just did a scan of the climate control module and it looks good.

Do you have an ATC control head or a manual control head? The control head is in charge of whether or not the compressor is requested, the ECM is in charge of doing it. There is some compressor clutch engagement torque compensation that happens and the ECM controls that and clutch engagement so the...

I appreciate all the replies and info.
What determines the Tstat setting?
It does not show up in the diagnostics. As far as the ECU looks all systems should be go.

Shouldn't it first turn the pump on in order for it to "see" the low pressure? I thought the 85 PSI would be within spec to turn the pump on. I realize its low once its running and have a local shop who built all the lines and did the first charge 7 years ago so I will have them do the rec...