this just started happening. I’m in wisconsin & it’s cold outside. The fan sonetimes stays on after I shut the car off & will start running after I start it up in the AM. '98 wagon, & I’ve had it about 4 years. any ideas? I’ve checked the coolant level & it’s okay.
Do you have the defrost on? That starts the A/C and the A/C starts the fan.
The fan is controlled by a relay and a coolant temp sensor. If either of these are defective, the fan will continue to run long after the engine is shut off, or as soon as the engine is started.
Tester
No, the defrost wasn’t on.
How hot is the engine getting? If the thermostat is stuck closed, the engine can get hot enough to turn on the radiator cooling fan, regardless of how cold it is outside. Also, a stuck/sticking fan relay can turn on the fan. How hot is it getting inside the car? If it’s getting hotter than usual, the engine coolant may be getting too hot.
Check that heated coolant is going into the radiator. Does the radiator feel hot?
A defective engine coolant temperature sensor can turn the fan on.