where is the temp. sensor?

[winstonmei]

1998 Sable station wagon ( same as Taurus).

The heater is not blowing enough heat and it is identified due to the weak water pump.

I now just have the water pump replaced and I am expect a lot heat. To my surprise, it is blowing cool air ( the outdoor temperature is about 80 F degree (27 C degree)! It look like the air conditioner is now kept on even I turned the manual temp control to the red hot zone (clockwise most)!

Where is the temperature sensor located? ( not the thermsat which is working normal). I want to know if this is due to faulty temp sensor or the mechanic screwed out something when serving the car.

Winston

[irish30]

The engine temp sensor is not used for your climate control. It is a monitored sensor for the PCM to turn on the fan to cool the engine. It sound like you have a problem with your heater core, or the blend door inside the air box, in the dash. The blend door changes or mixes the air flow from the a/c and heat. If the the thermostat is ok then the upper rad hose should hot when the engine is at regular operating temp. If it is cool or just a little warm then the thermostat may be the cause as well.

[winstonmei]

Thanks for the reply.
The problem is that it seems the air conditioner keep running all time and could not be shut off. If the heater core is at fault then the air it blows should not be much colder than ambient temperature.

I am wondering is there any ambient temperature sensor which 'trigger' the air conditioner on/off?

Winston

Originally Posted by irish30

The engine temp sensor is not used for your climate control. It is a monitored sensor for the PCM to turn on the fan to cool the engine. It sound like you have a problem with your heater core, or the blend door inside the air box, in the dash. The blend door changes or mixes the air flow from the a/c and heat. If the the thermostat is ok then the upper rad hose should hot when the engine is at regular operating temp. If it is cool or just a little warm then the thermostat may be the cause as well.

[irish30]

The engine uses the ambient temp sensor for it's fuel strategy. If it is cold outside the engine will run rich for warm up purposes. The passenger compartment air management system doesn't really care what the outside temp is. If you are getting air that is cold and you can hear the a/c compressor running when you turn the temp selector, you may have a problem with the selector switch or the blend door.