Had a Chinese diesel heater installed in my 2018 Four Wheel Camper Hawk shell model. Tapped into the fuel tank of my RAM 2500. Lots of hours of testing done and it is exceeding my expectations for warm dry heat!
smile.amazon.com/gp/product/B09LHWFH7S/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1 This one. Used it over 50 hours now and down to 5F. Works great. The controller does come with this one.