Cabin fan fluctuates in speed.

[Juhler]

Hi

This is ny first post, so bare with me.

My wife has a Polo 6r 1.2 TSI Comfortline 2013, with automatic climatronic.

When driving the fan speed goes up and down, there is no difference if it is on auto or manual function. I recently changed the pollen filter, but that did not help. I also have access to VCDS, but there is no faultcodes related to the climatronic system.

Any suggestions? Google tells me something about a resistor or thermal switch, but that only seems to be for cars with manual A/C.

[RUM4MO]

Hello and welcome to this forum!

I don't have a good answer to your problem, but I thought that I'll post so that you don not feel ignored as a new member, I'd think that not many other people have had this issue with an auto HVAC system in a VW Group car.

I'm not sure what effect the sunlight sensor has on an auto system when operated in non auto mode.

I'm sure that that system alters the motor speed by another means like pulse width modulation and so never ends up with the resistor problem.

I've never had any problem with any VW Group I've run that all have had auto HVAC systems.

One final suggestion, maybe with the ignition turned off, remove the pollen filter and reach in and see if the heater fan motor is easy and smooth to turn as it could have faulty/failed bearings.

[mirceaculita]

does it first go full blast, then stops for a while then slowly picks up again?

[Juhler]

Thank you for your replies.

It varies depending on the set speed, and obviously it is easiest to hear at high setting. The pollenfilter is change recently, but will try the manouvre of turning the fan manually.

I do not think it has anything to do with the light sensor.

[Juhler]

Small new update, when hitting the recirkulation button, it behaves normally. So it might be related to this. Will invistigate further.

[wb31576]

I have the same issue, so am interested to hear if there are any further updates!
My polo is 2013 GT model.
Am also new to this forum.
Thanks all!

[Vdsky]

Hello!
I Have exactly the same problem! Is there a solution? Experience?

[Vdsky]

Small new update, when hitting the recirkulation button, it behaves normally. So it might be related to this. Will invistigate further.

Exactly the same, you solved problem? What was solution?

[Juhler]

Small new update, when hitting the recirkulation button, it behaves normally. So it might be related to this. Will invistigate further.

Exactly the same, you solved problem? What was solution?

Hi, sorry for reply after months. But pressing the recirculation button only fixed the problem at that state, returning to auto made the cabin speed fluctuate again.

I am in the market for selling the car, so I have started looking at this again as I never got around to fix it. I believe its a heater actuator which is defect, but not sure which and how to replace yet.

[RUM4MO]

Remember that fan speed is under the control of the controller, so it can end up getting slowed/speeded up if the controller thinks that is necessary.

[Juhler]

Remember that fan speed is under the control of the controller, so it can end up getting slowed/speeded up if the controller thinks that is necessary.

Hi, that also sounds plausible. I would prefer to fix this myself, and not having to go through the dealer shop.

I am trying to locate the correct part number, but can't find the controller in this picture. Is it number 10?
https://volkswagen.7zap.com/en/rdw/polo ... 820020/#10

[ciclo]

At first, I suggest doing a basic setting of the ventilation flaps in the control unit (climatronic). I seem to remember that it can be done with VCDS.

If the problem still persists, you will need to investigate whether the potentiometers for the flap control motors (4) are not damaged.
With the multimeter, check that the resistance on pins 1 and 3 of the T6 connectors increases and decreases evenly when turning the gear.
For example: (use translator) https://www.drive2.ru/l/485024541777592498

The fan control/regulator can fail, but I don't remember that it has had a high incidence around here.
The N24 series resistor in A/C systems with manual controls is more likely to fail.

[Juhler]

At first, I suggest doing a basic setting of the ventilation flaps in the control unit (climatronic). I seem to remember that it can be done with VCDS.

If the problem still persists, you will need to investigate whether the potentiometers for the flap control motors (4) are not damaged.
With the multimeter, check that the resistance on pins 1 and 3 of the T6 connectors increases and decreases evenly when turning the gear.
For example: (use translator) https://www.drive2.ru/l/485024541777592498

The fan control/regulator can fail, but I don't remember that it has had a high incidence around here.
The N24 series resistor in A/C systems with manual controls is more likely to fail.

Thanks, I will try basic setting in VCDS. I could not find a solution to doing it with out VCDS as it is possible on other climatronic versions.

Edit: Basic settings did not help.

[pierre78]

Hi! i have a similar problem - the ac fan speeds up and down with a will of its own. Its not on auto and it only happens when the car has been driving for say 15 minutes or so.
Did anyone actually get this problem fixed? If so how?

[pierre78]

does it first go full blast, then stops for a while then slowly picks up again?

Hi! i have that problem. i could have the fan on say, two bars - then after ive been driving for 15 minutes the fan will go full blast, back to zero then to my preferd setting. Then it keeps doing that. Have you hade this issue and did you get it fixed? if so how? Struggling over here.