Ok so I have a cooling fan that will not operate when he car reaches temp. I have replaced the fan switch, ( the one in the thermostat housing) the thermostat and have done a complete radiator flush. Now i have heard the fan switch can go bad, so i took off the connection and bridged it with a wire and the fan works... I also switched around all of the relays in the fuse box (the heater motor, defrost and cooling fan) and they all work... I also test the new and old fan switch by dipping it in boiling water and the connection closes on both (so the old one is still good). So the relay, fan switch, fan motor and wiring are all good... WTF is the prob.

 

bleed the system properly, bubbles will cause the fan not operate properly

 

x2 make sure the system is bled

is the car even oveheating?