Hello, I already read a little bit and took some information with me but I miss the point on the i. Have Ford Escort year 97. The heat exchanger was defective. ie. water leaked out and thus cooling water empty. Heat exchanger bridged. Now a new problem occurs on which the fan motor does not start. Engine overheats and water boils out. I pulled the plug from the thermoset and bridged but the fan does not run on. If you turn on the air conditioning then the engine runs strangely The switch can only control a relay which then gives juice to the fan. Is this true (because of the control of air conditioning) and if so where is the relay? One said that there are also on the board which are and not only the ones on top of it the “easy” to change. Maybe someone has mercy again and helps me further.