Which of these goes in the water inlet housing where the thermostat goes? 92 3VZ-FE 6 cyl...

 

The switch probably has one wire while the sensor has two.

 

They both have the exact same two wire connecter on them.
I bought the Coolant Temp sensor but when I went to replace it, the threads were too small. It wouldn't fit the thermostat housing.
So I looked at the Radiator Fan switch, and it had the proper size threads, but was a little bit longer.
All the manuals I've looked at only make it more confusing, cuz one will call it a sensor and the other will it a switch.

 

In my Haynes the 1MZ-FE V6 shows two water temp SWITCHES at the thermostat housing and NO temp SENSOR at all. "A" is on top and "B" is on the side of the housing. "A" should show continuity only when cold. I'm assuming Toyo is using the two switches as an alternative to a sensor. The difference in thread is so as not to be able to mix them up.

 

Great... my problem solved... thanks.