Thermoking Tripac Apu not coming out of standby

Check fuses.

 

Do you have a bunk heater? Does it come on?
My apu has a power switch inside the exterior cabinet. Did yours get switched off?

 

Check the small wire going to the starter,they break off sometimes.Theres a big wire going to the starter and a small wire,bolted onto the same lug.I think the small wire senses the voltage.

 

If you have a laptop,look for the USB cord coming out of the apu panel under the bunk.Plug it in and a little program will come up.It will show you everything about the apu,clear codes if it has any.
I had a cabin temp sensor failure,Thermo King shop in Houston replaced it.

 

Mine was the trigger wire fell off the truck’s ignition switch.

 

Yep. It's the sense voltage wire. It tells the system what voltage the alternator is putting out. There's a 2 or 3 amp fuse on that wire. If it's bad the APU will typically start then shut down and throw a code. The alternator test doesn't happen until after the unit starts.