Fan cutting in far to late

[Ron41]

Hi all, my fan won't come on until the motor is really hot, it actually stunk of hot water last night before the fan would kick in, then the fan kicked in for about 10 seconds then went off again, this car has never got to this hot before the fan would come on, it used to come on all the time but lately it doesn't, i am not going by the temp gauge either, the car really smells of boiling water before the fan will kick, this surely isn't right, would it be my ecu temp sensor causing this ?
I checked the fault codes and nothing come up regarding it, only 76 & 78 codes.

thanks for any help

[paulsautoelec]

fan switch sensor possibly faulty about $25 ( coolant temp switch)

[227shanno]

that happened on mine, think they replaced the above and some sort of relay, in the little black box clipped next to the radiator

[Ron41]

Thank mate, I will get a new one.

[hako]

G'Day Ron, just an observation, but if you're smelling boiling water/coolant it may indicate that the radiator pressure cap is not sealing properly and not pressurising the cooling system. Unpressurised, the system will boil at 100 degrees Celsius whilst if the cap is working properly the system will hold pressure to 1.35Kpa (or 20psi) and the boiling point goes up to 125 degrees Celsius.
So what I'm getting at is that it may not be the sensor. See this article for a better explanation:
http://www.caradvice.com.au/156/radi...-pressure-cap/