I'm trying to flush out a problem with my 2013 S60. Changed the thermostat due to dash message of high heat. I realize that the cooling fan may not be running. It will turn on when you turn on the A/C, but I haven't heard it run after a drive. What triggers/ sends it info to spin? How does a DIY'er check that it is getting the information to turn on? Is there a sending unit or module that controls it? I would hate to bring this to Volvo if it's a 'simple' fix.

Does the fan spin when you twirl it with your finger or a stick? engine cold and ignition off for safety. If it does not spin, the fan is defective.

When you find the sensor, disconnect it and short the wires with some conductor (a piece of wire)

If it runs, the sensor is faulty. If it does not run, the fan or wiring may pe the problem.

A complicated fix may be a blown head gasket of a failed engine.

Bypassing the dealer may be a poor choice.

Any decent mechanic should be able to find the fault - does one service your car now?

Does the fan spin when you twirl it with your finger or a stick? engine cold and ignition off for safety. If it does not spin, the fan is defective.

When you find the sensor, disconnect it and short the wires with some conductor (a piece of wire)

If it runs, the sensor or wiring is faulty. If it does not run, the fan may pe the problem.

A complicated fix may be a blown head gasket of a failed engine.

Bypassing the dealer may be a poor choice.

Any decent mechanic should be able to find the fault - does one service your car now?

Are there any codes stored in the OBDII? One possibility is the Coolant Temperature Sensor. It should be located near the thermostat housing. Also make sure all the connectors are secure.