Technical Engine Cooling Wiring Diagram

[DaveHolmes]

I checked in 'Guides' but don't see one, but is there a specific simplified wiring diagram for the engine cooling system? There is a sender unit, two cooling fans, two relays, sensors etc, and it is almost impossible to extract an accurate picture from ePer or from all the printed wiring diagrams where I also cannot decipher the wiring colouring. I also suspect that the positions of the bulkhead relays differ from car to car, and am wondering how one tests them?

 

[DaveHolmes]

I am adding to my own thread here! Can anyone also explain how the whole cooling system works please? i.e. "As the system warms up, the engine temperature sensor talks to the xyz" and so on.

 

[s130]

See: https://www.fiatforum.com/downloads.php?do=download&downloadid=416

 

[wapper]

As the system warms up, the ECU reads coolant temperature sensor and turns on the engine fan(s) via relay. There is one relay and one fan on non-A/C cars, and two fans/relays on cars with A/C.
The main fan switches on at 95C and off at 93C, the second fan at 100C/98C.
The rest you can find in service manuals available via link above.

 

[DaveHolmes]

S130 and Wapper thank you for your responses. True to form the downloads don't work for me - I don't know why. It opens up the manual files 01 to 35 but when opened I wait for the download then 'open file' and it takes me to an error page where it says check the log for reasons. Of course one then searches for the log, and THERE ISN'T A 'LOG' anywhere. Thank you for the description of the 'modus operandi' of the cooling system!