A/C NOT WORKING 2019 KENWORTH T680 PACCAR MX 13 EPA 20

Body Control Module (BCM) is going to be the problem. I went through this on a 2020 T680 where I didn’t know if I would have A/C, cruise control, or dash lights. Those were the three things, if I shut off the truck, I didn’t know if I would have them, when I started the truck.

How we diagnosed it was there was power to both blades of every fuse socket. That means every system has power. We tried a jumper on the compressor, but, that resulted in nothing, because the rest of the system wasn’t being signaled to activate by the BCM. My employer refused to replace the BCM, because they felt it wasn’t a sure enough diagnosis. If a system has full power, demonstrates inconsistent behavior, it’s almost always going to be the component controlling it, which is the module. Pretty simple concept desk drivers can’t comprehend.

 

I don’t know. But, I’d say to look for something that looks like the pic. I can’t remember if that’s on the firewall or not. I don’t bring home the truck, so I can’t look.

 

Great answer. ☝️