ECT sensors

[Bob90lx]

Hey all, I'm new to the site and I'm currently dropping an SHO engine into my 1990 ford probe. The SHO is a 92 mtx. My question is regarding the electronic coolant temperature sensors. There appears to be two of them, one on the line leading into the heater core, and one on the lower intake manifold near the t stat. Any ideas what each one does? I could be getting around to switching over the computer and wiring harnesses soon, so I've been trying to further educate myself prior to that happening. Any and all help is greatly appreciated, thanks!

 

[yamahaSHO]

There are two by the Tstat (opposite sides) The 2-wire sensor is for the PCM and the single-wire is for the gauge. The other you are refering to is for the EATC to keep the heat from blowing (opening the blend door) when the coolant is not warm, IIRC.

 

[Bob90lx]

So the main sensor for the PCM is on the intake manifold, and the one
on the coolant line to the heater core is used for the fan with the climate control?

 

[AREA 91]

Please read this again.

There are two by the Tstat (opposite sides) The 2-wire sensor is for the PCM and the single-wire is for the gauge. The other you are refering to is for the EATC to keep the heat from blowing (opening the blend door) when the coolant is not warm, IIRC.

The sensor you want is located on the right side of the thermostat housing. This is a 2 wire sensor for the PCM (computer).
It is below the throttle body and is not on the intake manifold itself.

 

[Bob90lx]

Thanks for the info, yamahaSHO. I didn't see the single wire sensor on the left
at first, but after having another look at it I can see what you're talking about. I'll be removing the sensor on the coolant one to the heater core. That's the way I assumed it worked, but I was told by somebody that the sensor on the heater core line was actually the main sensor for the pcm. Thanks again!