Alternative APU System I saw last night.

[Lonestar10]

I priced a new tripac when I was thinking bout new truck I was told 11.5-12k installed.

You can get a used tripac yanmar engine for 800-1000 bucks.

Rebuild it for maybe 800 bucks. Put cutout style oil pressure and water temp sensors to kill the run circuit if something goes wrong
Run the oil pressure first so while cranking it sends power to temp sensor then temp sensor to run relays for fans and fuel cutoff relay.

You could probably build a bolt or weld together frame for 150-200 bucks

Put a new ac comp and alt on it for 500 bucks or less
Buy all the parts for any evap box and condenser or build your own for 1000-1200 with all new hoses, low/high sensors and some type of thermostat

Or find a way to tie the apus ac pump into trucks and put electric fans on the condenser and key off power to the trucks HVAC system

Put an ignition switch in the cab for run power and starter and a momentary switch for glowplugs relay.

Get a $120 eBay Chinese espar clone with lcd control screen

Or have Rawze teach you how to code and use an Arduino setup and run it all off that.

I think 3-4 grand and you would have a basic tripac setup