How this fan speed switch works?
 

Hi guys. Does anyone know how this fan speed switch works?
My 1984 930 coupe have two similar switch (one for the AC system in the center consol, and this one located near to the heating and ventilation control unit on dash).
I'll appreciate any help, thanks!
Best,
Leandro
http://forums.pelicanparts.com/uploa...1542635795.jpg

Being more specific, my question is:
That switch should turn on the additional blower as soon as it is changed from zero to speed 1, 2 or 3?
Or its ignition will depend on the temperature (thermostat)?
I ask the question, I know sounds silly, but what happens is that I have never turned on the heating system and I have many doubts with it, especially with the automatic heating control that comes in my car.
When I move the swtch from position zero to 1/2/3, nothing turns on, and what I want to know if, to do the test, I must put the automatic heating control knob (between the seats) in position DEF (max. heat and not thermostatically controlled), assuming that if the blowers do not turn on, then I should check the fuses, relays, etc ...
Thank you!

Well on my '84, that switch is connected to the blower fan located in the smugglers box, and works no matter what position any dash controls are at or even when I had the auto control box between the seats.
I ditched all my A/C and now use that fan as an auxiliary fresh air blower when it gets warm out.

Mark

Thanks Mark, I appreciate your comment. On my '84 930 the switch that works as you said is the one located in the center console (bottom right of the photo in my first post, right side of the radio fader); the same switch...
Best,
Leandro

Hi guys. Done!
My system work perfect...
I put the automatic heating control knob (between the seats) in position DEF (max. heat and not thermostatically controlled), and the blowers turned on, then when I moved the switch from position zero to 1/2/3, the speed changed correctly. I live in a warm country, so when the automatic system is controlled by the thermostat, it never turn on because sense hot temperature and not cold to run.
Thank you!

The HVAC system in our cars are ridiculously over complicated and completely unintuitive.
Like Mark, I took off all of my a/c and ditched my center console / auto heat.

I agreed - that HVAC is mindbogglingly counter-intuitive. I keep this in the glove box of my '86 930

https://i.imgur.com/cjiiogD.jpg?1

Haha that’s funny. I wish I had one off those 15 years ago. Took me forever to figure it out on my first 911.