On the 750j is not heating all the time.wonder if someone has a pic wher all hoses go and how many actuators the have. 1t0750jxlhbd208670
Looks like a live heater core. What doesn't heat up, the cab or the engine? My 6068 engines have had the plastic water pump impeller fall off, and the result is no heat in the cab, but, since they have a hydraulic cooling fan, the engine never overheats, but the fan runs nearly constant.
Cab heat heats then not.and if it's heat the higher the rpm the hoter it's heating.
Actuator for heat door is circled. But, I'd be more inclined to blame the controller or thermostat.