Water temp. Sensors
 

What are the names of the three water temp. Sensors that are right before the thermostat. I want to replace them but the auto store has no idea what I'm talking about. Then they try to sell me a sensor that doesn't go on my car.

You're probably only going to be able to get from a dealership or a Toyota parts dealer. Have you tested them? No need to blindly replace them.


Attachment 3765

I have not tested them. I have a n/a I don't have the fan switch or the a/c sensor I have the other two and one more that goes in the top of the housing by the bvsv

does anyone know how to test the functionality of the AC coolant temperature sensor and the radiator cooling fan switch? Using a volt ohm meter, should there be continuity when its at operating temperature or before starting the engine? Do the sensors connect when it gets a higher than average temperature or is it a resistance sensor that can be measured?

I don't recall ever needing anything other than a pot of boiling water and a multimeter to test any of the car's temp sensors. The details about testing the sensors for the A/C system are covered in the TSRM.

http://www.cygnusx1.net/Supra/Librar....aspx?S=AC&P=1

Its on Page AC-33. They are called They are called water temperature switch No.2 and No.3. Found on the 7M-GTE E/G model only. The diagrams are a bit tricky to interpret.
It looks like the N0.3 switch causes the radiator fan to come on when the coolant gets to
100 C then shut off at 95 C. So there would be no resistance at the sensor until it gets to
100 C. The diagram for the No.2 A/C coolant switch is less clear.

http://www.cygnusx1.net/Supra/Librar...aspx?S=AC&P=33

No 2 is open until 112?C then it closes until temps drop back down to 107?. The illustration is confusing because it's mirrored from the next one leading you to expect continuity UNTIL 112?...

Ok, I have them backwards. Its clear the the number 3 closes at 100 and opens at 95C.
Probably to run a fan. Its the number 2 switch diagram that is not clear to me.

Refer to the TEWD and the TEWD's tech notes. It'll probably clear it up for
you.

http://www.cygnusx1.net/Supra/Librar...x?S=Main&P=140