Fellas. .. I have an overheating problem on my gs300 mk2 1998 . It's done just on 100k miles ..been serviced on all its life at a Lexus dealer....till now ..Bit short of Cash and live 250 Miles from a Lexus dealer.
i just changed the thermostat correctly myself and it's still has the same problem.
thermostat doesn't open.
fans don't come on even when I turn the air con on....which by the way doesn't work the clutch doesn't seesn to engage on the compressor ..
I have tried bleeding the system but because the thermostat doesn't open to let me....heater on full temp.
I drained the radiator which looks in great condition ...????
I fitted a new radiator cap.

maybe water pump ?
maybe coolant sensor ?
maybe a fuse ?
maybe a blokage ?

needs some ideas and help from you smart fellas...
cheers
​​​​​​​Chris.

 

Have a look at this wiring diagram. There's a few components that you will need to check.

- Make sure the fuses are not blown (50A FAN MAIN, 30A CDS FAN and 30A RDI FAN)
- Test out the fan relays (FAN NO.3, FAN NO.1 and FAN NO.2)
- Test the thermo fan switch (unplug it while ign is on and see if the fan turns on)
- You could test the a/c pressure switch too by by-passing it

The other things to check after this would be your fans and wires.