Trying to figure out why the radiator fan was not running when my motorhome was overheating, I was getting the alarms but not the final warning to shut the engine down. We had just drove for 3 hrs without incident towing a GMC Canyon with the outside temperature in the upper 80's. We stopped to get a bite to eat and I shut the unit down while we ate, then proceeded on our way home. I drove about 15 mile on level highway and the unit over heated. I was able to pull off the highway to investigate the problem, when I went to the rear of the unit with the motor started I notice the radiator fan was not turning. After the motor cooled down the fan was turning and we were able to proceed on home. What I am wondering in why wouldn't the fan be turning if the unit was overheating? The unit is a 2002 National Tradewinds with a 350 horsepower cummins engine and a 6 speed Allison transmission, and it does have the side radiator. The radiator was cleaned and the thermostat changed. Looking for any advice what to look for. A similar incident happened about 1 year ago after stopping for fuel.
Thanks in advance. Puzzled