Electric fans runs after car is shut off, drains battery

Passat battery drains after a few days new battery fitted charging rate is ok can you help 1.8 w reg

Having the fan run on for a bit after the engine has stopped is not abnormal in itself, but 20 minutes sounds excessive.

If the fan does eventually shut off, I'd consider changing the thermoswitch (this is a sensor screwed into the radiator somewhere near the bottom, with a pair of wires connected to it - to change it, you'll need to drain the cooling system).

If the fan stays on continuously until the battery is completely flat, see what happens when you unplug the wires from the thermoswitch. If this stops the fan, you need to replace the thermoswitch. If it doesn't, then you need to examine the wiring associated with the switch and the fan, looking for damaged insulation.

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