2003 S40

martin9586 · Post by **martin9586** » 05 Jun 2011, 19:53

does anyone know if the a/c fan under the hood is supposed to stay on the entire time the a/c is running or is it supposed to turn on and off as needed?

Post by **jimmy57** » 05 Jun 2011, 21:37

There are two and the larger one is a two speed and the smaller one a single speed.
ECM will run the large one on low at something around 200 psi and then go to high and add the small one at 250 +/- psi.
If it is a cooler day the car has cooled down the fan will cycle when you idle and the fans usually go off at a bit over 25 MPH due to air movement.
If a/c isn't on the fans will be staged based on how hot the engine gets.