Need help keeping my truck running at idle. No APU

I know on our Volvos you can set the trailer brake and not the tractor, then bump the idle up. It'll stay running all night.

Honestly though, we really only idle when its really hot or really cold. We also have Webasto's.

 

The spike is what I call the lever for just applying ur trailer brakes opposite side of the steering colum from the signal indicater

 

I drove a 379 Pete that had a auto shut-off all I had to do to idle all night was to watch for the blinking light on the dash right before it would shut down and ether press on the accelerator or the brake once and touch nothing else!
Hope this helps!!!