Apply Now!

What's wrong with our ThermoKing APU!!

piattteam

piattteam

Active Expediter
Our ThermoKing APU has worked great for the first 2 weeks we've been driving our truck.
Now, it runs for a few moments and shuts off, with an ENG fault, and pops the reset button out.
Coolant and oil are fine.
We are having trouble with our vehicle A/C and have had it serviced- to no avail- twice, by T/A.
Could faulty vehicle A/C have affect on APU?
 
mrgoodtude

mrgoodtude

Not a Member
Don't think the vehicle A/C has anything to do with the APU.
If it is popping the reset button may be an overload issue, did you try running with the thermostat off 1st? (Just power for a few then turn on cooling).
 
beachbum

beachbum

Veteran Expediter
Owner/Operator
If its a new APU take it back to TK it's under warranty, as for your truck A/C take it to a real A/C repair shop not a truck stop. If the truck is under warranty take it to their shop not a truck stop.
 
davekc

davekc

Senior Moderator
Staff member
Fleet Owner
Several things. For the truck itself, if it had a blown or replaced compressor, it is likely you have debris in the system. Especially if it keeps going out and they find no freon leak. It is likely clogging the orifice tube or clogging up the expansion valve.
Only real fix is to replace condenser and dryer and run pressurized nitrogen through the system.
On the generator it could be a couple of things. Does it run with AC off? If so, the condenser fan isn't working or the capacitor needs replaced. It is getting hot and tripping the breaker.
If it shuts down regardless of AC, it is either a fuel problem or a faulty temp/oil sensor.
Each sensor can be bypassed to determine which is bad. On the fuel, it would be wise to check the inline filter as many times those are ignored at service.
 
Last edited:
jansiemoo

jansiemoo

Seasoned Expediter
As DaveKC said, check the inline fuel filter. (I can't remember- are there two fuel filters on there?) We had the inline fuel filter replaced once and it shut down repeatedly like you are experiencing. There was air in the lines, and they purged, purged, and purged before it would stay running.
Oh, and don't let TA touch your apu. Nothing good can ever come of it. :)
 
piattteam

piattteam

Active Expediter
beachbum, thanks. Used truck, APU. We are taking it to an International shop, after delivery tomorrow.
 
You must log in or register to reply here.
Top