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Radiator fan relay

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Old 02-25-18, 06:15 AM
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Kretek234
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Default Radiator fan relay

Hi everyone, I need help to figure out how to take the fan relay. I tried to wiggle it and pull out but doesn’t budge.
My fan turn on as soon as I turn the key, the car doesn’t over heat, and the fan off when I turn the key off.
There are 3 relay, fan no1, no 2 and no 3. What are the 3 relay for? Is only has 2 fan.
I just guess that no1 is low speed and no2 & 3 is high speed.
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Old 02-25-18, 10:38 AM
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MikeFig82
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The relay itself has 2 locking tabs. You'll have to pry both sides of the plastic black housing.

See pic for lock tab orientation.

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Old 02-28-18, 09:20 PM
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TW99GS300
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You sure it's not the temp sensor on the radiator that's causing your fan issues?
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Old 02-28-18, 09:39 PM
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Originally Posted by TW99GS300
You sure it's not the temp sensor on the radiator that's causing your fan issues?
Also the 2GS has a fan switch on the radiator.
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Old 02-28-18, 10:31 PM
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Exact one I'm speaking of. If that's unplugged or defective the fan will run constantly.
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Old 03-01-18, 03:55 AM
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Originally Posted by TW99GS300
You sure it's not the temp sensor on the radiator that's causing your fan issues?
Thank you for your suggestions, I just try to pinpoint the problem. Where is the location of the radiator temp sensor and switches? Do you have a picture?
The problem is when the key off, the fan stop. As soon I turn the key on the fan start running.
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Old 03-01-18, 04:55 AM
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Originally Posted by Kretek234

Thank you for your suggestions, I just try to pinpoint the problem. Where is the location of the radiator temp sensor and switches? Do you have a picture?
The problem is when the key off, the fan stop. As soon I turn the key on the fan start running.

The switch is on the right of the radiator facing the engine. You'll have to get underneath the car and look up. It should be next to the drain plug. Hex head switch sticking into the radiator.
Last edited by MikeFig82; 03-01-18 at 05:13 AM.
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Old 03-01-18, 05:42 AM
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Is this a switch or a thermistor? I'm guessing it's a thermistor which changes resistance with temperature. With an ohm meter, measure across its terminals when cold. Warm the engine and measure across the terminals again. The resistance should decrease.
Cold ~ 2500 ohms
Warm ~ 350 ohms ?

Something like that. If it doesn't change or is leaking, replace it.

Also, do your can tests with the Heating and A/C turned off. When on, the A/C can be called upon and this by itself can trigger the coolant fans to run.
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Old 03-16-18, 06:11 AM
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Originally Posted by TW99GS300
You sure it's not the temp sensor on the radiator that's causing your fan issues?
The temperature gauge in the dashboard is normal and never overheating.
Do you think is the relay problem? What is your opinion.
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Old 03-21-18, 03:02 PM
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Originally Posted by Kretek234

The temperature gauge in the dashboard is normal and never overheating.
Do you think is the relay problem? What is your opinion.
finally I tested the #1fan relay, I think is OK I heard the click when I apply power.
now I have to check the temp sensor on the radiator.
What else do I need to check.
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Old 03-21-18, 04:02 PM
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Originally Posted by Kretek234

finally I tested the #1fan relay, I think is OK I heard the click when I apply power.
now I have to check the temp sensor on the radiator.
What else do I need to check.
The temp sensor on the radiator would be my first guess. It should be bad if the radiator fan is having those symptoms.
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Old 03-22-18, 04:13 AM
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Originally Posted by MikeFig82
The temp sensor on the radiator would be my first guess. It should be bad if the radiator fan is having those symptoms.
Thank you for your suggestions, do I have to drain the coolant to replace the temp sensor?
Thanks.
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Old 03-22-18, 04:46 AM
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Originally Posted by Kretek234

Thank you for your suggestions, do I have to drain the coolant to replace the temp sensor?
Thanks.
Is there any other sensor related to the fan that I need to check?
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Old 04-01-18, 06:56 PM
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Originally Posted by MikeFig82
The temp sensor on the radiator would be my first guess. It should be bad if the radiator fan is having those symptoms.
Just checking the price for fan switch/ temp sensor, is about $100. Online, Lexus dealer charge $125. Wow, that’s expensis I better make sure that this part that cause the problem,
with electrical part you can get stuck with it if it’s not wright. Any other sensor related to the fan that I should check?
Thank you very much for your help and suggestions .
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Old 04-01-18, 10:09 PM
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According to rock auto, they have the radiator fan switch around $13 to $17 plus shipping:

http://www.rockauto.com/en/catalog/l...an+switch,4312

Yes when you remove that sensor, coolant will be coming out so have a large bucket ready unless you are super fast at swamping this sensor out.
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