That, if its the part Im thinking of, is NOT a magnet. Its a resistor for the "low" setting on the cooling fan. The connector has a ground and 2 12 volt positives. The low setting turns on one 12 volt leg, which goes through this resistor, which makes the fan spin at a lower speed. The "high" setting is the other 12 volt pin which goes direct to the fans motor to run it at full speed.