What controls when the heater starts?

[DeTomato]

I have a digital climate A/C system. With the colder weather I've just had my heating on Auto today, but without A/C on.

What I noticed was no fans were turning and no air was blowing out on engine cold start on Auto.

Only when the engine reaches the first notch marking on the dash engine temp gauge does the Auto air start blowing through in the cabin.

At the second notch marking the auto fan air blowing doubles up. 

Is this normal?

What enables the cabin fans to kick in when on Auto?

Is there a way to get the cabin heater fans to kick in earlier when on Auto?

Thanks.

[oldcodger]

Hi,

Not something I have experienced, though I do not usually use Auto, as it tends to get a bit noisy when it turns the fans high; normally just use manual with fan speeds 2 or 3.

Will try your condition next time I'm  out, though it does make logical sense because if the water temp is below the cabin temp its only going to cool you down if it switches the fan on.  Once water heat is detected it will keep ramping up the fan speed until the desired temp is met.

Usually set off with my fan switched off these cold mornings and drive a good mile before turning the fans on with the temp set to Max.

[oldcodger]

Hi,

Yes, mine is the same.

Started my cold engine, temp set at 21c and pressed AUTO but the blower does not come on.

Pressed the temp down and the blowers stays off right down to 16c, but then press down again to  COLD and the blower comes on full blast.

[DeTomato]

Ok so that's both of us seeing the same.

So apparently the Police are very quick now to stop any driver with misted, iced or partial window obscurity on ANY window in a car - 3 points & a big fine for driving like this! So take care if you're tempted to drive off in freezing cold weather.

With no manual, I need the best way to get the car heating up inside more rapidly if/when the frost and ice starts. Any ideas with a climate control A/C unit?

[oldcodger]

Hi,

Not heard of the Police doing that, though understandable from a safety point of view.

Always use the AC Demist button  when things steam up, usually after getting wet before getting into the car.

I'm fortunate that I can put the car in the  garage to keep the frost / ice off.

Really no other way to clear the glass other than letting it run for a few minutes before setting off.

There are the little cheapy 12v dashboard heaters, though think they will be quiet poor on a really frosty day, plus too much sudden heat and the glass could crack ?

Seems there are still some Start Up heaters you connect to the water hoses but they need mains electricity.

Think there was a  guy from Norway posting in this forum recently, perhaps they might have a more effective method ?  - worth a PM.

 

[alan333]

Any vehicles I've used with climate control work the same - the heater fans don't kick in (or do, but only at the lowest speed) until the engine starts to warm up, then increase as the engine warms.  Usually there's a screen defrost button which puts the air flow to the screen, puts the air con on (even tho it doesn't work below at certain temp, usually 3 or 5 deg), and puts the fan on high.

The police can't insist you have all windows clear.  You need the screen, the front side windows and the wing mirrors clear (ie the same field of vision that a van/truck driver has at all times) .  Except if you don't have a n/s mirror - then you also need the rear window clear.  

[Mooly]

Just manually alter the fan speed to its lowest setting when cold. That will turn the blower fan on (and also enable the A/C if ambient conditions are suitable). That will 100% over ride the Auto setting. Also manually set the desired airflow direction.