Hi, For anyone who is wrestling the a electric fan switch on a 200 Tdi engine
The mechanical fan on a 200 Tdi engine was replaced with an electric one (make kenlowe). We have used a PRC3505 temperature switch and mounted it on top of the thermostat housing. The thermostad housing is only threaded on vehicles fitted with airco otherwise use a tap M22x1.5 mm on the aluminium housing. We did not drill a hole in the thermostat housing just added a little bit oil to improve the contact so there cannot be any coolant leakage. The switchs works at 88 centigrade.
Jerry