Tripac Apu smoking

Its my truck, I financed it n m working for landstar. I dont want to idle my truck cause i know its not good for the engine and could also get me a ticket, so until I get this fixed ill be suffering a bit, hopefully the belt will help.
The smell was in my bunk. I got to the receiver early and was going to take a nap, the temp was 80+ so I turned it on cool and laid down after 10 mins i started smelling what to me smelled like fireworks and I say that because it wasnt a normal burning smell it was weird.
But when I make some money Ill def be taking it to thermo king I called the one here and they told me 150+ per hour and thats just to do a diag.

 

I hear you, its my first APU def dont want to mess it up, im going to replace that belt being its cheap, n im sure the dealer would charge an arm and a leg for it, so Ill get that done before taking it in. Ill have the money saved up in a couple of weeks and try to book a load to one of those locations and have em look at it. Thank you for all the help I really appreciate it, you guys are awesome!