Thread: What the? My viscous fans just kicked in and now they won't turn off!!!

Just trying to check tune on my disco and I plugged the timing light into the plug that I thought was number 1 (front drivers side plug) and not only did the motor kind of wane and then stall, but those two fans in the front of the grill kicked in and they stayed on even after I turned the car off. They only just shut off now (couple of minutes after car was turned off)...what's the deal with that?

Originally Posted by Young Angus

The air conditioner wasn't even on when they kicked in but it was when the timing light was plugged into what I know think was the wrong spark plug and the engine did some funny things and the fans kicked in. It could have just been a strange electric disruption that messed the computers around and caused the fans to kick in but they stopped a couple of minutes after the car was turned off which was good...I would have been really worried if they had kept going because nothing seemed to turn them off. Not turning the car on and off, turning the air con on and off, not nothing. But they're off now so touch wood that was just a random weird thing...

Ok YA, Those fans are aircon condenser fans. They come on as soon as the A/C is switched on that's normal.
THEY ALSO come on if the sensor ontop of your thermostat cover sense that the coolant temp at that point is high and switch the thermo fans on also. They are on a timer, after shutdown they can run for a period of about 10 mins then switch off.
This is to cool things down. As you know your engine oil is cooled by the radiator and also your gearbox has a cooler condensor in front of the radiator.
If it didn't switch off after 10mins then I would worry.
Saying that since I had my Radiator rodded ,mine don't come on like they annoyinglyEVERY TRIP did before the rodding. That tells me that something was not right, there was a hot spot.