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Discussion Starter #1 (Edited)
Does Anybody Know Where I Can Find The Cooling Fan Senors, Just Rebuilt A Salvage '01 Is300 Car Is Finished But My Fans Just Wont Go On. Where Is It Located, What Does It Look Like?
 

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Had the same problem anyone ?

I check the fuse, relay, changed the Radiator fan switch, and still donest go on.. even with the ac on. Fan still doesnt work...

Could it be the wiring ? Anyone have a fan diagram ?
 

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I just went through this same exact thing on my 02! Also salvaged it took a hit in the nose after it was all put togethar the fans wouldn't turn on. Do your self a favor and disconnect the sensor in the radiator and jump the connector with a wire. This should turn the fans on as soon as you put the key in the on position.If they turn on your wiring is good. If they do turn when you do this its either one of two items either the radiator sensor (pictured right) or the fan relay (pictued left). Both are pictured below,chances are the relays burned out this is what happened to me. I'd replace the relay the coolant sensors rarely go bad start with whats the cheapest obviously. Hope this helps if not I'd check your wiring almost all of mine had been ripped out. This was the case for me so I hope this info is helpful GL

 

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I just went through this same exact thing on my 02! Also salvaged it took a hit in the nose after it was all put togethar the fans wouldn't turn on. Do your self a favor and disconnect the sensor in the radiator and jump the connector with a wire. This should turn the fans on as soon as you put the key in the on position.If they turn on your wiring is good. If they do turn when you do this its either one of two items either the radiator sensor (pictured right) or the fan relay (pictued left). Both are pictured below,chances are the relays burned out this is what happened to me. I'd replace the relay the coolant sensors rarely go bad start with whats the cheapest obviously. Hope this helps if not I'd check your wiring almost all of mine had been ripped out. This was the case for me so I hope this info is helpful GL

thanks for the advise, really appreciate it, sorry i took so long to thank you, was in a bad bike accident, just getting back into the swing of things, i'll try this, & thnx again.:)
 

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thanks for the advise, really appreciate it, sorry i took so long to thank you, was in a bad bike accident, just getting back into the swing of things, i'll try this, & thnx again.:)
i was told at Lexus that the relay in your picture is for the day time running lights (DRL) are you sure that this is what fixed your problem with the fans??:blush:
 

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i believe the sensor on the right is the one that controls when the fan should turn on. I have been having same issue. I need part number of that relay
 

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i believe the sensor on the right is the one that controls when the fan should turn on. I have been having same issue. I need part number of that relay
Yes, you're correct, that screws into the bottom of the radiator and closes at 203*F. There are three fan relays that all come on when that switch is made. Two are exactly the same while the third has a normally closed contact(and a 5th pin), which is relay 2.

85927 90080-87026
COOLING FAN RELAY

85927A 90084-98032
COOLING FAN RELAY NO.2

85927B 90080-87026
COOLING FAN RELAY NO.3

2002 IS300: OEM Electrical (SWITCH & RELAY) Replacement Parts

All three need to be working for both of them to come on at high speed. You can verify if the relay is good or bad by applying battery power to the silver terminals on the relay and the contacts should change state. Also make sure your 30A RDI and 30A CDS fuses are good as well as the 10A ECU-IG fuse.

I have no idea why the title indicates there is more than one sensor for the fans. There is another coolant temperature sensor that's variable but is only responsible for the ECU and cluster gauge.
 

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If your thermostat isn't opening up, i don't think coolant is exiting your engine from the bottom hose which thus wouldn't even touch that sensor as its right next to the lower radiator hose, causing it to be cooler than it should be and never getting to the temperature to kick the fans on. Did you install your thermostat pointing correctly?
 

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If your thermostat isn't opening up, i don't think coolant is exiting your engine from the bottom hose which thus wouldn't even touch that sensor as its right next to the lower radiator hose, causing it to be cooler than it should be and never getting to the temperature to kick the fans on. Did you install your thermostat pointing correctly?
I could be wrong Wing, but i don't think it's physically possible to put it in backwards. Coolant at the lower hose may stay cold if that guy isn't opening. Good point. I think that's what OKCIS's problem is too.

PR Fiebru, your top rad hose should get hot as the engine warms up. When the temperature gauge reads close to midline, then the thermostat opens and the bottom hose should get hot. I've heard of new thermostats being bad right out of the Lexus packaging too. Make sure the system is bled as well. You can try jumpering the two wire sensor and then turn on the ignition, both fans should come on at high speed. If they don't, then it's an electrical problem.

Try turning the AC on. Both fans should come on at slow speed and only relays 2 and 3 are energized. When the pressure switch is closed, all three relays come on and fans run at high speed.

So that's how you can verify if it's a poor cooling issue or an electrical issue with the rad fans. All three are very critical.

Oh ya...and the pick of the relay above IS the DRL master relay(1&2). lol
 

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Oh its definitely possible....I did it myself. Make sure you don't rush yourself and pay attention to what you are doing when you are re-assembling your accessories on your engine. Luckily you are able to change the thermostat when its on the car....cuz I would have been PISSED!! haha
 

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You need to make sure your block and head are filled with coolant. The thermostat retrieves it heat from the coolant, not the heat transfered from the housing. What I would do is pull the upper radiator hose off and fill it with coolant until it starts to flow out, throw the hose back onto the radiator and overfill the rad. You need to keep that radiator over filled until the thermostat open up.
 
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