E30 M3 radiator temperature switch: other BMW twin-temperature switches use the same M14x1.5 port
A PistonHeads thread checked the catalog. The E30 M3 radiator thermo-switch port is the common M14x1.5 thread, so other BMW two-stage fan switches fit physically: 61311378073 (91/99 °C) or 61318361787 (80/88 °C, itself reported as ended in 2012). Check that the 3-pin plug matches and that the switch temperatures suit how you use the car. Experienced owners add that if the cooling system is healthy, a lower-temperature switch is not needed. Also check the low-speed fan resistor and wiring if the fan never comes on.
Parts / numbers mentioned: 61311378073 (91/99 °C), 61318361787 (80/88 °C), M14x1.5
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