I am new to group I would just like to say hi to everyone. I would also like to see if anyone can help me with my temp gage problem PLEASE!!!. The gauge starts out at half and goes all the way up just below red. The car is not getting hot at all have replaced thermostat, temp sensor for gauge, one in thermostat housing. Any other help please. Does anyone know where the other temp sensor is. I am also looking for shop manuals for the car and owners manual too. The car is a 1990 ls 400

 

look at this photo - the gray sensor with an arrow pointing to it is the sensor for the gauge only

the green sensor is for the car's engine computer (ECU) and affects how the car runs

there is also a sensor on the thermostat and one in the bottom corner of the radiator

try replacing the gray gauge sensor first, it is cheap and easy - and use the genuine Toyota one from the dealership, it's only about $15

 

the car is NOT getting hot? when you touch the upper radiator hose, is it hot?

 

^^^^^ I'm pretty sure he just meant it's not over heating.

 

I hope for you its the sensor. If not than the gauge itself is going out. Can be changed out rather easy but a little costly.

 

Not necessarily, it could also be wiring between the gauge sensor and the gauge, or could also be the capacitors in the cluster main circuit board

 

Yep. Very true start simple.