HVAC Automatic blower speed delay at start-up: Adjustable?

Hello, VagCom friends,

Is anyone interested in checking to see if the HVAC Auto blower delay at start-up is adjustable via VagCom? Many high-end cars have this feature, to prevent extremely cold air from being blown into the cabin.

Currently, our car's blower delays about 2-3 seconds, then it immediately goes to 3 lights on the blower dial, which is WAY too much air when it's 30f out. Kinda defeats the usefullness of the "auto" feature, doesn't it?

I also find the blower, while crusing down the road, fully warm, stays on 3, which is just too much air movement...and noise... IMHO.

I agree that both of these issues are worth tweaking.

I never use the auto button so I never have any issues with blower/fan speed, I put it where I want it.

I'm surprised it doesn't wait for the coolant temp to come up. Even my old Mercedes waits to turn on the blower until the coolant gets to 100*F. And then it starts out slow and goes faster once the coolant gets warmer.

Compu 85...my 93 Audi S-4 was very similar to your Benz. I'm surprised this doens't wait longer.
I hope it's changeable...

I think the blower turn on has to do with the electric heater element. Theoretically it can produce heat right away so it ramps up. However, the element can't really produce that much heat (only about 1kw) so I agree it would be better if it went to a lower setting, then cranked up once the coolant was warm.

How long after it starts blowing before you can feel the effect of the electric heater? This may be the reason for the quick start - and if it works correctly, it shouldn't stay cold that long, should it? Perhaps the timing is right but the electric heater is not working correctly?

If its anything like the mk5, it takes 2 mins to get luke warm air. When it's single digits outside, 2 mins is pretty awesome.

Yeah. Mine warms up enough to keep the windows from fogging and thats about it. Seat heaters provide the rest of heat until the engine warms up.

3 is a little noisy too, but seems to be the default setting. 2 would probably be better.

3 and above is noisy on my jetta too, it's the german engineering and lack there of.

TomB said:

3 is a little noisy too, but seems to be the default setting. 2 would probably be better.

Click to expand...

Our Roadmasters start off (with too little wait in case of heat, too) at hurricane force when the current temp is vastly different from the thermostat setting. The closer the current temp gets to the setting, the more the fan speed slows down, using many more gradations than the 5 visible in the display and accessible by manual fan speed control.

Does the Passat not slow down? Or is 3 its lowest setting to settle at automatically?

I was thinking about this... I bet the car knows it has the elec heater so it turns the fan on right away. If you recode the ACC for a car that doesn't have the elec heater I bet it will wait for the coolant to warm up.

-J