Originally Posted by EngineerMike
per post#30 he's getting temp alarms, per coupla posts radiator fan is not turning at idle. I'd call those problems needing solution IIWM.
Some engine fans are designed on diesels not to turn until the engine requires additional cooling. Its possible to drive long distances without the fan being engaged. Having said that I am not familiar with this his particular fan controller valve.
Getting a temp warning up steep grades in summer COULD be the result of not shifting to the proper gear to keep from lugging the engine. A perfectly functioning coach and or diesel can over heat if lugged very easily on a steep grade during a hot day.
I find it hard to imagine the coach could be driven normally in all other environments except just in road with a bad cooling fan and not overheat on a regular basis.
I could be wrong. I have been before. I will be again.