Why is the 70 series AC different? (1 Viewer)

[350HJ75]

this may be a dumb question but apparently there are none.

every other car i own has AC as a button - on or off

but a 70 series has the dial, my FSM calls it a temp. control resistor.

does this mean it varies how much work the AC compressor does somehow? i would really like to know

 

[AndrewHadji]

I think its an american thing, my Peugeot and Citroen overseas had a similar variable resistor. The 305 had a dedicated knob for it.

 

[Gun Runner 5]

this may be a dumb question but apparently there are none.

every other car i own has AC as a button - on or off

but a 70 series has the dial, my FSM calls it a temp. control resistor.

does this mean it varies how much work the AC compressor does somehow? i would really like to know

On mine the inner ring is fan control while the outer ring is the thermostat. (Controls the workload of the compressor) That's the only setup that I have seen on a 70 Series.

 

[AirheadNut]

It varies the duty cycle of the AC compressor, meaning that you can adjust how cold you want the AC. Some older American vehicles have a similar feature, but it is just based on the setting of the temperature knob.

 

[roscoFJ73]

I think they did it to save 50mm of space on the dash.

 

[350HJ75]

ah ok well that answers my question, i wonder why if you have hot/cold air control you would need to vary compressor load too?

 

[roscoFJ73]

Being able to turn the aircon on full bore and add heat as well is the quickest way to demist the windscreen. I don't know if Toyota intended it that way but it works well

 

[JuanJ]

Being able to turn the aircon on full bore and add heat as well is the quickest way to demist the windscreen. I don't know if Toyota intended it that way but it works well

Hello,

x2. The 70 Series windshield is big enough to require full bore AC to demist every now and then, at least in my experience.

I suspect they did it that way to save space as well.

Really hot days may require the compressor working at full load, at least to cool the interior enough to a bearable temperature. After that, less load keeps the temperature. The latter applies for both the compressor and the fan, at least in my experience.

Not as sophisticated as current climate control systems, but it works.





Juan

 

[350HJ75]

first i had aircon questions, now i have problems... i have recenlty got the aircon working (as my car never had a compressor since purchase) with a new compressor and regas. however now the ac is always on regardless of the position of the outer ring, i want to remove the switch and test it as per the below FSM diagram.



So does it normally have a 'click' in the rotating of the outer ring to turn the AC on? as the diagram shows an on/off part of the rotation travel but not a resistance which should be reading with the off position. or is the off position no continuity at all???