I have a 1992 Lexus LS400. The dash light is indicating that the coolant is low but each time I check the coolant, the level is full. So I am guessing I have to change the sensor. I bought a coolant temperature sensor but I don't know where to install it. I'm posting the picture of the car. I am hoping you guys can help me with the location of it. If you can download the picture and use a picture editor and circle the location with red, I really appreciate it. Bob

Top view of the 1992 Lexus LS400 engine

 

I had the same problem too with the radiator light turning on and off from the dash. It's not the coolant temp sensor, it's the coolant leveler sensor attached on top of the coolant reservoir tank. It's a screw top that pops out easily and the plug from the end of that. Once you replace that, the light will disappear.