Is200 Rad Fans Not Kicking In

[Kevinlfc17]

Hi can any body help my rad fans r not kicking in checked the two 30amp fuses in the engine bay there fine any ideas anybody thanks

[steve2006]

There should be a thermo switch normally mounted on or very near the radiator which could be the problem, if you locate it and short the 2 terminals on the plug the fans should kick in.

Are you sure there is a problem? With the present outdoor temperatures I doubt the fans would come on anyway, unless the engine is overheating.

[Kevinlfc17]

I just been lookin round the switch at the bottom on the drivers side is broken and not plugged in is there any way to test it I no on older cars u could put a wire across the two terminals and that would switch the fans on can u do the same on the lexud

[sjrainsford]

The radiator fans operate at two speeds. Low speed is when both are connected in series. This only happens when the Aircon is switched on. This would at least tell you that the fans are working. They come onto fast speed when the pressure switch operates in the air con system.

However, you can just short the two wires together that connect to the water temperature sensor, this will bring the fans on into full speed. This is located at the bottom drivers side of the radiator and operates at around 95 degrees C approx.

The fans are operated by three relays. If I remember correctly, the water temperature switch operates no1 and 3 relays via a diode pack.

[Kevinlfc17]

Just done a bit of lookin round the fans don't come on when air con is on I think it needs re gassing the temp switch is broken so going to get a new one I shorted the two wires and the fans kicked in

[sjrainsford]

I'm not entirely sure if the fans come in straight away with the aircon, I can't remember without looking. But, does your aircon compressor clutch engage when you turn the aircon on with the engine running?

[Kevinlfc17]

Don't think so I no on other cars when it needs re gassing the air con compressor does not kick in

[sjrainsford]

Yeah, that's normally the case.

[Kevinlfc17]

Thanks for your help any way

[Ahmedtchicco]

Hi.i have car lexus is200 it was overheating I change radiator and thermostat and heat sensor in radiator and fan is not working I check all fuse is ok I bleed air out still fan not working is any one now what the problem please.thank you

[ColinBarber]

13 hours ago, Ahmedtchicco said:

Hi.i have car lexus is200 it was overheating I change radiator and thermostat and heat sensor in radiator and fan is not working I check all fuse is ok I bleed air out still fan not working is any one now what the problem please.thank you

The temperature switch sensor in the radiator is for the cooling fans. Disconnect the wiring and short the two pins in the plug - the fans should come on (with ignition on). If they don't then you have an issue with the power to the fans - check the FAN fuses and the fan relays. If the fans come on then you know the power to the fans is ok and the fault is with the temperature switch on the radiator.