Issue with HVAC system - Random shut off

I am going to be driving a bit this week and will see if my problem is resolved or not. I am going to also look through all the documents you gave me to see what my next step should be. I'll look into replacing R6 relay. Already spent a good portion of money on this truck. Mostly things that happen after 500k miles.

This is very helpful. Thank you very much!

 

Please post back when you find the solution to this problem! My 2012 freightliner JUST started doing this same thing. Code SYS 25 and my air in the cab is completely out. Air in the sleeper still works for now. The pressure was low for awhile. Restarted by truck a couple times and it is now blowing in the sleeper as it should be. Still nothing in the cab. So any info you find would be very helpful as I'm about to have to pay for the same fix (I'm not mechanically inclined)

 

And now the fan in the sleeper is back at half strength smh FML

 

Typing from my phone.
I have been driving 5 days now and the issue is resolved. My issue was that a wire broke from the starter and was messing with the volts. I feel dumb that I didn't think about why my volts where sitting in the red on the dash. Learned my lesson. Happy that it didn't cause more damage to the electronics.

I haven't researched what wire that was. My theory is that it was shorting the system or over volting and causing it to cut out.

Thanks for the documents you provided me. I'll keep them handy for other issues. In the meantime I'll post another issue I am having. When I get back home.

 

I had two Cascadia with similar issues!

On one, an alternator wire was loose and grounding out causing the AC to mysteriously stop.

On the second, the master cut off switch was going bad: 14$ switch. Of course I put in a new starter, alternator, ac controller while chasing that one!

 

I would start with seeing what that code could mean. Try searching it here and in Google. I have found some topics here in regards to the blower fan. Look them up too. People had issues with the blower fan going out and causing what sounds like yours. I think it's about $80. I also replaced the control module ($300) which was a waste but at least I have it if my current one breaks. I would start with seeing if your blower fan is going bad.

If your battery guage is in the red or maxing out then you could be having an issue like mine.

 

Good to know. I had trouble finding issues with mine around. This thread should hopefully at least help people start figuring out the issue if they ever have it. At least what to look for.

Mine was the wire being torn off. But my AC worked when the system would work. I may be confusing alternator with starter. My wire that was torn off was on what I believe was the seloniod. Drivers side between frame and engine.

 

Yea I'm gonna have to figure something out here asap. My voltage is showing normal. My oil pressure gauge is actually higher than normal for an idle and it's not staying at a constant idle. It's slightly fluttering off and on. Never noticed that before so idk if that's normal or not.
Also getting code CHS 71. I guess I have some research to do
I did just get my Sam cab replaced about a month ago. Maybe they ####ed something else up or maybe now that that's working properly, other #### is starting to go smh

 

More and more bs keeps popping up. Now when I go to turn the key to ACC before I start it, on my 2012 freightliner with the D N R L shows on the center dashboard, it shows as 88 instead of N (neutral) for a few seconds. This thing is a money pit

 

Do you have an auto trans? You should look up diags for your auto, sounds like you have a tranny problem, too.