Radiator fan not working properly

2002 TOYOTA CAMRY
180,000 MILES • 2.0L • 4 CYL • 2WD • AUTOMATIC
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IRNSH117
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Radiator fans not coming on even when reaching normal operating temperature (on the dashboard gauge) Fans only comes on if the connector to the coolant temperature sensor is removed (unplugged) when the engine is cool and also when it reaches operating temperature. On another note, there's also no thermostat on the cooling system. I don't really need it because of the climate I'm living in. But is it possible that that is what's causing the fans not to kick in? Because it already reached operating temperature on the gauge. Shouldn't the fans kick in?
Note: the car hasn't overheated yet, no signs of overheating, but I need to know why the fans are not coming on. thanks
Jan 28, 2022 at 4:12 AM
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IRNSH117
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Note: both fans are working when the A/C is turned on, but never comes on when reaching normal operating temperature (without A/C).
Jan 28, 2022 at 4:27 AM
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SQM
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Hello,

If a vehicle does not have the thermostat, it will not reach the proper operating temperature.
So, if that does not happen the coolant temperature sensor will not send the signal to the ECM to turn on the fan.
When the sensor gets unplugged, the ECM sees an open circuit and turns on the fan as a safety measure, as it does not know the temperature of the engine.

The operating temperature on this vehicle is 203F
So, it is possible that the vehicle might not be reaching that temperature and the ECM does not see any reason to turn it on.

And fans will come on with A/C, to provide proper cooling, it is a normal operating procedure.

https://www.2carpros.com/articles/how-a-coolant-temperature-sensor-works

The coolant temperature sensor can be tested, by checking the resistance.

I have attached the test procedure for the sensor below.

Please let me know if you have any questions.
Thank you.
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Jan 28, 2022 at 7:25 AM
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IRNSH117
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So, you're saying that even if the temperature gauge reaches the middle between hot and cold, without the thermostat the fan won't come on?
The engine type is a Toyota 1az fse (Caldina 2002) not a Camry, couldn't see Caldina on the selection so I just put Camry.
Jan 28, 2022 at 1:41 PM
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SQM
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Unfortunately, we don't have access to the technical data on the Caldina, so I cannot provide the exact data of the operating temperature.
But regardless of the thermostat, unless the coolant reaches its operating temperature, the fan will not come on. The only exception would be if you turn on the A/C or even max heat.
So, if you are not experiencing any overheating, it should be just fine.
Jan 28, 2022 at 2:02 PM
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IRNSH117
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Okay. Thanks.
Jan 28, 2022 at 4:34 PM
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SQM
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You are welcome.
Let me know if you have any questions or concerns.
Jan 28, 2022 at 5:22 PM