My gauge in the dash went bad, i replaced the sending unit by the upper return radiator hose and the gauge in the dash to no avail. I was told there is a single wire temperature switch that is located somewhere on the engine block. Funny thing, most people don't even know about it and the ones that know that it might have on, have no idea where it is. I have even called teh dealershiop and they don't know up from down it seems.

3.4L V-6 96 4Runner 4x4 auto. is it down by the Thermostat on the bottom of the engine near the return hose? If you know where it is, any specifics would help bc I have taken the timing belt housing, intake manifold and anything else I can but still cannon find this sensor

 

Similar problem in this thread, the sensor you're looking for is at the back of the engine

https://www.yotatech.com/forums/f2/m...runner-144982/