[ChrisC]

Not exactly a new topic, and pretty basic, but I haven't found the answer to this having searched the forums.

I would like to know where the temperature sensor used by the climate control to sense outside temperature is located. Why? Beacuse it seems to me that, if we are to run the 'a/c' function of climate control in winter, as is recommended to keep it in good order, it is only possible to do so by warming the outside temperature sensor and triggering the cooling system. Is my logic correct? Look forward to members advice.

 

[matt747]

Alternatively; you can over-ride the auto function and reduce the required cabin temp until cold/chilled air comes out of the vents.

 

[Essex Escy]

the air sensor is located just inside the passenger side lower grille......

*as found out when removing bumper for bulb change..........*

am i right?

 

[turbo paul]

i do believe you are right mr essex

 

[TheBoy]

Surely the climate uses interior temp gages to detremine the temperature vs your desired temp. You would have to heat up the interior then whack on the climate on really cold days to give it its workout?

 

[ChrisC]

Many thanks guys.

Matt - teh lowest temperature I can set is 18C. Since this is way above outside air temp at this time of year, I don't think your suggestion would work for me. Is it possible to set the sytem up to deliver a lower minimum cabin temperature?

 

[ChrisC]

Theboy - that might be one way, but perhaps with a low outside temperature, teh system might just pull in cool outside air wqithout making use of the a/c?

 

[Essex Escy]

a/c isn't just about cooling air.........

its about "conditioning" it......

so therefore, the a.c can still work, even if you aint cooling the cabin, but heating it up.....

 

[ChrisC]

Fair point, - presumably you are referring to dehumiifying along with temperature reduction as the two components of air conditioning. Since I don't have a hygrometer, its easier for me to confirm that the system is working by temperature measurements.

 

[Essex Escy]

no no, you can heat a car using a/c..........thus showing if its working.......

 

[TheBoy]

do you guys leave it on auto or econ in the winter? I always leave it on econ, even in the summer unless its really hot - dont like it drying me out when theres no need to..

 

[Essex Escy]

econ dude........and if you wanna be freaky........have it on neither

 

[ChrisC]

Essex Escy

You no doubt know more about this than do I. Are you saying that the a/c system is reversible - ie that you can heat or cool air to the cabin with the one system? I had assumed that when heating the cabin the a/c made use of a heat exchanger in the radiator circuit (just like vehicles without a/c). Please tell me if I am now on the right track!

 

[Essex Escy]

i dont know more.......and indeed you are trying to show that by using technical terms....

just go outside, put the a/c on to about 24/25 and see what happens.........the compressor works because it also dehumidifies, and keeps windows steam free....

 

[talk-torque]

Two points here. The air con compressor will not run with an outside temp of less than 5degC. If you turn the inside temp setting down to below 18degC, the display reads "low" and the system just cools, regardless of inside temp. Also, Essex Escy is quite right - as well as cooling, the job of the chiller in an air conditioning system is to dry the incoming air. The air is first cooled, which causes any humidity it carries to condense out, (hence the puddles under a standing car in the summer) and then reheated to give the desired inside temp. In a true air conditioning system, the air is also rehumidified in a controlled way, using steam or water mist, to a comfortable level, but cars don't have this facility, hence, with the cooling working hard in the summer, your mouth will dry out on a long trip. HTH.

 

[ChrisC]

Talk torque,

Thanks for this.

So, would I be correct in concluding :

If outside temp below 5C, cooling the cabin is achieved simply by drawing in external air.

If 5C < outside temp <18C, and climatronic set to LO, cooling/dehumidifying system will be activated.

I think you are also confirming that if cabin needs heating, this is achieved with a conventional heat exchanger matrix, as in non A/C vehicles.

If so,I can now check the system in my new vehicle, despite the weather!

 

[Essex Escy]

heat exchanger blah blah.......

the A/C HEATS THE CAR TOO..........

and the readout on the climate display is NOT outside temp, but cabin temp, as specified by the sensor on teh left and right of the climate unit......

the external tmep is displayed in dash......

 

[talk-torque]

Chris,

"If outside temp below 5C, cooling the cabin is achieved simply by drawing in external air."

- Correct.

"If 5C < outside temp <18C, and climatronic set to LO, cooling/dehumidifying system will be activated."

- Correct.

"I think you are also confirming that if cabin needs heating, this is achieved with a conventional heat exchanger matrix, as in non A/C vehicles."

- Correct, the system has two matrixes (?) the cold one is called the evaporator.

Essex Escy - The readout on the climate display shows two temperatures - the outside temp. and the desired, or set, inside temp. As you say, the external temp. is also displayed on the dash.

 

[ChrisC]

Roger,

Many thanks for confirmation.

Chris

 

[redgti]

You can however "foul" the system by removing the plug from the external temp sensor, in which case the outside temperature will be measured by another sensor which is located inside the cabin filter housing, therefore giving considerably higher outside temp. If the outside temp then reads more than 4 degrees C, and you have the climate set to AUTO or just not ECON, the AC compressor should engage. Don't be surprised if the outside temp reads -30 after you plug the cable back. It takes a few minutes for the temp to stabilize.