Weird question. I know there are two differen't sensors but which is which. I thought the sensor on top, right next to the thermo housing is for the gauge in the cluster and the one on the front of the engine is for the ecu. So I unplugged and installed an aftermarket gauge on the top one. You may be wondering what the hell my question is well... My gauge in the cluster still works! so i thought it was just stuck, nope. My engine started overheating and the gauge in my cluster went up right along with my aftermarket gauge???
Can someone help me out here? It was my understanding the top unit was for the gauge, front by fuel rail for ecu. How the hell is the cluster temp gauge still working??? It is not plugged in....

 

Did some research and found this thread, this is the sensor i was talking about
https://www.yotatech.com/forums/f116...olcano-209020/

From the details in the thread it sounds like it is for the ac unit. Can anyone else confirm this?
This leads me to believe that the temp sensor on the front of the engine is for the gauge in the cluster and the ecu? which brings me to my next question.
That gauge always sits halfway and never drops no matter how cold it is when i start the engine, but, if it heats up or overheats it does go up. what the hell is going on here. Could it possibly be sending wrong signals to the ecu too? and causing it to keep in open mode?

 

above the thermostat is for the AC
green under the throttle body is for the ecu
black under the throttle body is for cold start timing?
on intake manifold, aft of the thermostat and forward of the egr is for the gauges

Now if I could only find part numbers...

 

on my 86 22RE..cold start injector time switch is black on left..green on right is temp sensor.This located under t-stat housing.

 

That green temp sensor is for the ECU for engine temp for air/fuel ratio.