APU won’t work


Elibob

New Member
ThermoKing APU control lights up but nothing works, where do I start looking
 

I'd look at the 50 amp fuse down by the alternator
After you press the reset button on the side of the control box

What he said.

Any faults showing up on the control panel?

Any warning buzzer when you turn it on to indicate it is even trying to start up?

Power to the starter? (Assuming either of the above two things is happening)

None of the above? I would get it to a thermo king shop. I highly recommend the one in Joplin, MO.
 
The control panel has the yellow triangle after a few seconds. The buzzer in the APU doesn’t buzz and haven’t checked for any power yet, been on the road in old truck. Moving into new truck with the APU issues tomorrow and will check for power and fuse, I’ve had the fuse issue with almost every ThermoKing APU I’ve had. Thank.
 
There's a fuse kit that moves the fuse from down by the alternator and moves it up by the air filter.

It's been posted here before.

I made my own since it's just for a maxi fuse.


 
It’s the newer Evolution but I found the problem today. This truck has been sitting since August of 2019 and a mouse had gotten inside and chewed thru some wiring under the bunk around the spray foam filling where the wiring goes under the cab. Replaced 2 fuses,spliced and heat shrinked the wires and refoamed the hole and all is working. Thanks for the add and suggestions.
 

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