Messatsu

Ok, i've searched high and low for an answer but no dice. So here it goes.

Last week my car overheated, coolant from reservoir was boiling/spilling over and all that mess. Thinking it was the cap/thermostat i replaced both, and drained my RED coolant. Coolant was red with no signs of oil. I also checked the oil, with no signs of coolant.

Anyways, as it turns out my cooling fans are not operating. I checked both switches, the one on the bottom of the rad. and the one on the thermostat housing, both read fine, opened and closed at the proper temps... installed them and my fans still DONT run.

The temp gauge still climbs and the fans still dont turn on, WTF!? they only run when i disconnect the switch/sensor on the bottom of the rad.

Are the fans supposed to temp. turn on when you turn on the car?or ONLY when the engine is running and as reached proper temperature.

HELP

Messatsu

anyone? anything?

LeX2K

Try these tests from the service manual if possible and report back.

Messatsu

Well, i finally got my fan switch (on rad) hopefully i get to install it today. All signs pointed to it, so im crossing my fingers.

Messatsu

so, is the cooling fan supposed to turn on as soon as you turn on the car and then immediately shut off? or just when it reaches operating temp?

Messatsu

anyone? well, i replaced the ect switch on the bottom of the rad. but still no dice on the fans kicking in, the car can reach almost 3/4 and still no fans.

I did however move the efi relay to one of the fan realy and the fans kicked onto low speed though. I tested all the relay's to what seemed to be okay.

Someone, anyone give fellow lexus owner a hand

Messatsu

Old thread but i thought id share what i found out about my overheating, well first off it was not my fan switch or anything like that, It turned out to be the water pump. The blades were made out of plastic and were so corroded that they just broke off... all of them.

Toyota said it was the HG's, which it wasn't but i changed them any way. Im just left wondering why any company would make the blades on a WP plastic?

All said and done the car runs like a champ.

mechie007

Hi New Guy Here - I have a 1997 Lexus es300 that had a front end impact. Leave it to my Son - Full story avaiable upon request. Long story short. I went to salvage yard and pulled from Clip from 1999 lexus ES 300. Although all the part fit right up. The car starts and runs, but I have no cooling fans. I paid $100.00 to replace both Fan Relays. I have also by-passed the Fans directly to the battery and they work. When I giggle the relays into the fuse box I can get the fans to come on. I have check all the cable but still no -go. Ideas what to check next. I have completed all the tasks of the comments on this thread. I am still at a loss. Thanks...

LeX2K

Maybe the fuse block was damaged when the car was hit?

ES300NZ

maybe the spade clip in the fuse box, on a specific relay is only 'just' not connecting.

mechie007

I decided to let the engine run to see if it will reach an over temp reading. The engine did not exceed mid-point temp reading on the guage. I then drove the car for 1hr or so, still the car did not over heat. Running very well. At time I would pull over and quickly pop the hood to see the Fan's spinning at random speeds. Question: Is it possible that the FANS only turn on when a certain temperature is exceeded? That is what I am thinking is going on. I have traced all the cable from the Fuse Block and all connections are solid. I am thinking that we are good to go, prehaps the FAN's from a 1999 ramp instead of always on with the smaller 1997 fans.

SBayLocal

This thread really helped, especially the FSM diagrams. I own a 1999 Lexus ES300. Fans weren't kicking in unless I had the A/C going, causing overheating in stop and go traffic, but fine on the highway. Unplugged Coolant Temperature Sensor Connector (the one near the bottom of the radiator), and the fans were fine, so I'm guessing its the Sensor.

Does anyone have the part number for this part? I've been researching online and I think it might be 89428 - 33020, but I was told that was for the #2 sensor / switch, and the diagram is showing that I need the #1 switch. Anyone know if they're identical? If not, anyone know what the correct part number would be?

Thank you for your help in advance, you guys are great.

ES300NZ

There are two, they are different. one is on the radiator, the other is on the engine, USA drivers side, above the trans, side of the engine, on a pipe, it's a brown plug, single wire/pin.

SBayLocal

The one I'm looking for is on the radiator, had to get it from the bottom as it's plugged into the bottom of the radiator.