Switch for fans
 

For the Impreza

Is there a thermo switch built into the radiator that controls the fans or is it to do with the ecu switch that’s close to the coolant temperature sensor on the block?

I’m extremely paranoid about the amount of times that my cooling fans come in.

The classic has 2 sensors,the single wire sensor for the gauge and twin wire for the ecu,both sensors are close to each other behind the alternator.
I'm unsure if the newage has the same set up?

Can you datalog to see what temps the fans kick in? Should be 98*c

No access to datalog info, not until next month.

Assuming we are talking Hawk wagon

Both main and sub fans are controlled by the ECU. Operational conditions are shown on the test pages
There is a single temp sensor which serves both temp gauge and ECU requirements

Basic tests/checks procedures..........
Fans-main system.pdf
Fans-sub system.pdf

http://clarkdh.net23.net/NTL/Fans.PNG

Below is the section of the engine electrical system showing the coolant sensor and its connections.
G - goes to the combimeter gauge.(temp gauge
V -connects into the electronic throttle control system (common feed))
http://clarkdh.net23.net/NTL/Fans%20...t%20sensor.PNG

My bad, it’s the bugeye sti track car.

Assuming it's a UK bugeye ;)

Very similar setup - controlled by ECU single temp sensor

Fans wiring diagram
http://clarkdh.net23.net/NTL/MY02%20Fans.PNG

Sensor
http://clarkdh.net23.net/NTL/MY02%20...t%20sensor.PNG


Diagnostics

http://clarkdh.net23.net/NTL/MY02%20Fans2.PNG

http://clarkdh.net23.net/NTL/MY02%20Main%20Fans1.PNG
http://clarkdh.net23.net/NTL/MY02%20Main%20Fans2.PNG
http://clarkdh.net23.net/NTL/MY02%20Main%20Fans3.PNG
http://clarkdh.net23.net/NTL/MY02%20Main%20Fans4.PNG

http://clarkdh.net23.net/NTL/MY02%20Sub%20Fans1.PNG
http://clarkdh.net23.net/NTL/MY02%20Sub%20Fans2.PNG

The ecu tells the fans to kick in, there is no thermo switch controlling this, I know this as part of my map tweeks, I get the fans to kick in a few degrees earlier than standard,
the CTS is a 4 wire, and on the rear of the engine, get a cheap VAG lead and read what temp the ecu is being told it is, if it says 90 all the time, even when cold, then you know it needs replacing.

Could it be that these have been mapped to come in earlier? I’ll send a message to AF, see what he says. It was mapped before I got the car.