So after trouble shooting my coolant system like crazy I’ve come into another problem. My AC auxiliary fans aren’t staying on after shutting the engine off. They work when I turn the AC on, the fans themselves spin but after shutting off the engine they do not stay on to bring the engine temp down. It used to do it about 4 months ago when I first got it but I didn’t realize until now.

I have a new battery, I had the alternator tested, but I don’t know much about the electrical system. I also changed the engine temp sensor recently. Anyone got any ideas for me? 97 Disco 175k v8 4.0

 

The fans will only run if the temp is past a certain threshold I am not sure if it is 120F or something like that. if it is below the threshold it will just turn off when you shut the rover off.

 

Here is the description from the ETM.

 

So if the engine is below 100 Celsius after shut down the fans will not be on. That makes sense, thanks for the help

 

The fans work when I turn the AC on for sure, but I don’t believe they come on by themselves if my temps hit 212, and they often do.

 

Took me a few years to realize that my auxiliary fans only stay on after I switch off the engine if I leave the Air Conditioning switched on. My truck could be running very hot with the aux fans blowing but if I switch the AC off and then the truck off then the fans don't stay on after the truck is off despite being above the temp when they should be running.

I was taught to switch off everything every time when I switch off a car. Out of habit I switch off the radio, wipers if its raining, and fans. One hot day my wife drove and she doesn't switch off anything and the fans stayed on. Amazing!

Could just be a fault on my truck but the fan switch on the hvac has to be switched on for the aux fans to work. Maybe yours too?