Radiator fan always on

2002 TOYOTA SEQUOIA
230,000 MILES • 4.7L • V8 • 4WD • AUTOMATIC
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JAMESLUCE
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Radiator fan always on even when cold. I thought it was only supposed to turn on when gets to a certain temperature.
Aug 11, 2020 at 6:30 PM
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JACOBANDNICKOLAS
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Hi,

You are correct. It should turn on at a specific temperature unless the A/C is on. Is it only happening with the A/C on? Also, the defroster will do the same.

Pay attention to see if that is what is happening, and let me know.

Joe

Aug 11, 2020 at 6:54 PM
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JAMESLUCE
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No, it is on even when A/C is off.
Aug 11, 2020 at 7:00 PM
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JACOBANDNICKOLAS
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Okay, then either we have a short to power or there is an issue with a relay, or a faulty coolant temperature sensor.

Lets start by checking if there is a short to power. I need you to remove the fan relay to see if the fan turns off. If it does, then I need you to check the relay.

Here is a link that explains how to check a relay:

https://www.2carpros.com/articles/how-to-check-an-electrical-relay-and-wiring-control-circuit

The relay is in the under hood fuse/relay box. I attached a pic to help you locate it.

Let me know the results.

Joe
Aug 11, 2020 at 11:53 PM
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JAMESLUCE
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Okay, I remove the fan relay fuse then started the car fan stayed on. Okay, put finger on relay fuse had someone else started I felt a click. And I remove the fuse started the engine and fan still ran.
Aug 12, 2020 at 11:27 AM
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JAMESLUCE
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Should I move onto the temperature sensor?
Aug 13, 2020 at 9:52 AM
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JAMESLUCE
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Ignore that last message I was holding the wrong relay. I found the right relay felt no clicking pulled it out and fan still ran. Bought new relay put it in still the same thing happening.
Aug 13, 2020 at 3:21 PM
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JACOBANDNICKOLAS
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If you are removing the fuse, it shouldn't run. That indicates you have a short to power. When the key is on, another circuit is powering the fan. That is what I believe is happening on your findings.

Check as much of the wiring near the fan and make sure there is nothing wrong or causing this to happen. If you find nothing, then we need to remove one fuse at a time to see when the fan stops. At that point, we will at least know the circuit that is causing the problem. I will then look through schematics to see if I can locate areas where the two systems are close.

Let me know.
Joe
Aug 14, 2020 at 12:21 PM
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JAMESLUCE
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Okay, thanks will do.
Aug 14, 2020 at 12:45 PM
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JACOBANDNICKOLAS
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No problem; happy to help. If you have a chance, let me know what you find.

Take care,
Joe
Aug 14, 2020 at 5:01 PM