2G Passenger Fan always On

[gontijexx]

Hi there, my right side fan kicks in as soon as I start the car, I already replaced the sensor, but didn't work , I was wondering if I miss something, I swapped the relays on the JB but stayed the same, could be a bad ground or my ECU just blow?

 

[luv2rallye]

Is this something that just started?
Did you replace the 2 wire sensor or the 1 wire one? The 2 wire sensor controls the fans. 1 wire is dash temp gauge.
Is the car still stock with the factory 4 wire fans or are they aftermarket?
Did anyone rewire the fans?
2g fan operation: https://www.dsmtuners.com/attachments/fan-operating-mode-2g-jpg.86862/

 

[gontijexx]

Sorry that I didn't give full info, everything in my car it's stock.

I replaced the 2 wire, the question it's if someone rewire it but I don't think so, it's an issue that persue my car since the day I bought it. I already replaced the ECU once, fixed the harness on the 2 wire sensor (both fans were on high before). I also noticed that once hits the temperature the condenser fan kicks in.

 

[luv2rallye]

With the engine cold and just started, car not moving, and the 2 wire temp sensor unplugged, does the passenger fan still come on? If so, someone must have either changed the wiring, the ECU is bad, or reprogrammed the ECU to do that on purpose (some tuners cars run so hot (or in a hot climate) they do this - and many have asked me how to rewire the fans to stay on with engine on).

On a 2g with 4 wire fans, the fan speed is controlled not by voltage on a unique specific wire pair but rather voltage on wire combinations. https://www.dsmtuners.com/threads/cooling-issue-plus-wiring-the-fans-up.273645/#post-151311484

 

[gontijexx]

If i unplugged the 2 wire both fans come on, in any temperature, but this is how it works on every eclipse in Brazil because our ECU it's different i think. I will record a video

 

[luv2rallye]

Ok I forgot you're in Brazil. Ya all Eclipses are different outside the USA.

 

[gontijexx]

I forgot to mention that the fan only come on when I start the vehicle, in the ignition ON nothing happens, if I wanted to track this down where should I start?

 

[luv2rallye]

If i unplugged the 2 wire both fans come on, in any temperature, but this is how it works on every eclipse in Brazil because our ECU it's different i think. I will record a video

Are you sure about this when the engine is cold? I find that hard to believe even in Brazil since when the sensor is unplugged that would show as high (infinite) resistance on the sensor harness, which the ECU would conclude the engine is not hot, and so not turn the fans on - unless you have the AC on which forces the drivers (condenser) fan on (at least on all USA 2g models).

 

[chrysler kid]

Can you please confirm the “right side fan”. Are you referring to the condenser fan on the drivers side of the motor?

This fan should only be active with the ac switch turned on. It could be possible the relay is bad and stuck open or there is a jumper in the dust box under the hood the previous owner put in because the car was over heating at some point an wanted all fans on

 

[gontijexx]

@chrysler kid right fan it's the passenger fan or rad fan, I know the another one it's for AC

Are you sure about this when the engine is cold? I find that hard to believe even in Brazil since when the sensor is unplugged that would show as high (infinite) resistance on the sensor harness, which the ECU would conclude the engine is not hot, and so not turn the fans on - unless you have the AC on which forces the drivers (condenser) fan on (at least on all USA 2g models).

But this is how it is, @Lintu fans works just fine but if unplug the 2 wire the fans kicks in, with or without the AC, I will record a video when my ECU arrives

 

[gontijexx]

It was ECU caps