Is there one or two? Where is it, or they, located?

 

there are 2 one on drivers side head, for the temp guage
other on pass block? I think for the ECM.

 

My 85' has the temp sensor on the front of the manifold, and im almost positive it only has one. There is also a fan switch and some other sensors, but only one actual temp sensor. Try taking it out and cleaning off the tip of the temp sensor if it has any corrosion on it... mine was a little gummed up, I took a wire wheel to it and now it works fine (Auto Zone and Kragen didnt carry it).

 

you have a 85-89 90-up is different I believe.

 

OK, just looked atht eengien (not gonna happen after 31 Jan) 1 sensor by the thermostat (beside the sensor for the csv for those that have it), one in the front of the driver side head. Thermostat one is most likely for ecm, & head for gauge.

The fan switch is caddy corner from the drivers head in the rear of the pass head.

 

knew there was 2 but forgot where the second one was... I was thinking the fan switch as the other temp...