Help me interpret apu reading

Discussion in 'Heavy Duty Diesel Truck Mechanics Forum' started by TheMeatMan, May 25, 2026 at 11:19 PM.

  1. TheMeatMan

    TheMeatMan Bobtail Member

    5
    0
    Feb 15, 2026
    0
    So my Tripac evolution has been having issues lately. I’ve been waking up with it completely shut off with the red triangle and ‘eng’ light on.

    Sometimes when I start it it will blow cold for a minute but then the little frost icon will start to flash and stop blowing cold. The engine will stay on and the fan will blow but the a/c won’t kick in.

    I was able to get a reading of what’s going on when this happens and apparently the high pressure switch is kicking on and not letting it cool. I’ll post a picture of the reading as well as all the codes. The condenser is clean, condenser fan blows like it should and I wiggled the hpco switch and it didn’t cause a shutdown.
    IMG_2066.png
    As you can see the temp, rpm and coil temp are all high and the high pressure thing is open.
     
  2. Truckers Report Jobs

    Trucking Jobs in 30 seconds

    Every month 400 people find a job with the help of TruckersReport.

  3. TheMeatMan

    TheMeatMan Bobtail Member

    5
    0
    Feb 15, 2026
    0
    There were no codes during this. The engine was running but it wasn’t cooling. Here are the previous codes.
     

    Attached Files:

  • Truckers Report Jobs

    Trucking Jobs in 30 seconds

    Every month 400 people find a job with the help of TruckersReport.