I've developed a leak from the radiator fan switch and it seems to only be leaking around it and not through it, otherwise it works fine. I've bought a new washer to replace the old one and I'm thinking of putting some thread sealant on the threads of the fan switch which should hopefully stop all future leaks. The fan switch looks like a typical fan switch used across the board for many VW cars.
Is it a bad idea to put sealant around the threads? Some say that the threads need solid contact with the metal of the radiator as it acts as a ground and also it might interfere with the sensor temperature readings.
Car: 2004 Seat ibiza 6L
Mileage: 110000 km (63000 miles)