2008 Volkswagen Jetta • 12,900 miles

Just recently the electric fans will come one when the car is turned off and key out of ignition and locked. They will go on and off all day intermittent and it kills the battery. They use to have the fans come on as soon as you started and always stayed on until I turned off the car and closed the drivers door. Now the fans also wont come on when running but the temp doesn't go past 190 so it isn't running hot.
April 5, 2013.

Could be a faulty temperature sensor or a problem with the coolant fan control module.

Have a shop that's familiar with VW's look at it.


Apr 5, 2013.
Or even an a/c pressure sensor issue.

Apr 5, 2013.
Very unlikely that it's a pressure sensor or ECT.

On MK5, this is usually a faulty underhood fuse-box. This is how you test it.

Open the hood, and latch the hood latch or un-plug the hood latch connector (so that the vehicle thinks the hood is latched) and arm the vehicle (lock it). Take the cover off the underhood fuse-box, locate fuse SC14 or 15, they should be 10amp fuses. Simply check how much voltage is at the fuse. 2 minutes after the ignition is switched off and the vehicle is locked, there should be 0 volts at these fuses. If you have any voltage at these fuses, the fuse box has to be replaced. Typically you'll see anywhere from 3-5 volts, sometimes even as high as 7-9volts will be present. The corroded fuse box is what is activating the cooling fans to come on.

Apr 7, 2013.