no air from vents with AC on, or with recirc on. blower working.

[carl0s]

Hi, weird problem I noticed today. It was the first time driving the car in hot weather for almost 2 years (car has been out of use, and we rarely get hot weather in the UK anyway).

With AC on, the blower fan is working hard (as demanded), but I have no idea where the air is going - it isn't coming out of any of the vents.

As soon as I turn AC off, it blows out of the vents like you would expect. And it is cold too - for about 1 minute, which is the residual cold from the AC evaporator. Then it becomes outside-ambient air but blowing like it should.

So the AC system is working, but for some reason it is diverting air to 'god knows where' when AC is on.

At the same time, I noticed that with AC off, if I enable recirculation (manual-ON for recirc), the same thing happens - there is no air felt though any vents anywhere, but the blower is running properly and making all the noise it should when fans are turned up high.

Anyone got any ideas on this? No errors found when using a scan tool (Bimmerlink). I have ISTA on my laptop but had family round so haven't had time to dig any further. Google hasn't turned up any 'super common problem' results though.

Car is a 2014 Gran Coupe (M6).

[JBF650]

Originally Posted by carl0s

Hi, weird problem I noticed today. It was the first time driving the car in hot weather for almost 2 years (car has been out of use, and we rarely get hot weather in the UK anyway).

With AC on, the blower fan is working hard (as demanded), but I have no idea where the air is going - it isn't coming out of any of the vents.

As soon as I turn AC off, it blows out of the vents like you would expect. And it is cold too - for about 1 minute, which is the residual cold from the AC evaporator. Then it becomes outside-ambient air but blowing like it should.

So the AC system is working, but for some reason it is diverting air to 'god knows where' when AC is on.

At the same time, I noticed that with AC off, if I enable recirculation (manual-ON for recirc), the same thing happens - there is no air felt though any vents anywhere, but the blower is running properly and making all the noise it should when fans are turned up high.

Anyone got any ideas on this? No errors found when using a scan tool (Bimmerlink). I have ISTA on my laptop but had family round so haven't had time to dig any further. Google hasn't turned up any 'super common problem' results though.

Car is a 2014 Gran Coupe (M6).

as a safety the air should divert to the screen as a system default. Can you feel it coming from the windscreen vents when this scenario happens? perhaps turn the whole system off and on and let it reset. hit AUTO set the system to 22' with A/C button on with NO recirculate and see if the system calibrates correctly and directs air from the facia ( all the facia vents are turned on via their scroll buttons yes ? ). Under most circumstances you should have some air coming through the facia.
Another thought is if our cars have the AC system air direction 'controlled' through idrive. This is all waaaay overkill in my opinion anyway but might be an idea to have a look in ventilation and airflow part of idrive to see if some airflow settings have been manipulated...??? again I'm not sure if our Fseries cars have this but i suspect they do, maybe someone's played around with it.

[Qsilver7]

Question…what happens if you switch off the AUTO mode and select individual air directions?

When you DE-select AUTO & manually select the defrost, dash, or floor vent air direction…or any of the other combinations that can be selected from those three…do you still not get any air blowing from any of those vents?

[carl0s]

Hi all.

I fixed this today. It was the recirculated-air flap (circulating-air flap) stepper motor / actuator (part number 64119319037).

When I realised that the problem happens with AC off but recirc-on (at first I thought it was just when AC on), I suspected that AC was using the recirc even when I had it turned off. So I suspected it might be recirc related.

In ISTA I could see the setpoint value changing to 100% when AC was on, but the Actual value stayed at 0%. That confirmed the source of the fault.

I took some photos, however in my photos here I don't have one showing the 0% actual / 100% setpoint. Take my word for it.

I took the actuator out, opened it up, cleaned it with brake/clutch cleaner, regreased it with silicone grease (Superlube), and soldered the pins to the PCB. It seems like there was no solder at all on the pins to the PCB. It looks like they intentionally used pressure-fit pins that make contact on the insides of the PCB vias. Seems very odd to me. Unless it is a manufacturing mistake. Anyway I soldered the pins (no photos of them soldered, but it's only 5 pins or so, very easy, small tip)

I reconnected it and just held it in my hand, and it looked like it was not behaving - it kept seeing the Actual point at 17% then 0% then 17% then 0% again.. I thought oh well, I'll buy a new part - at least knowing what part is faulty. But I fitted it and ran the calibration and it calibrated perfectly, I saw the flaps move, and everything is now all good. If it doesn't last, I will buy that part, at least I know what's going on now. It was frustrating that my Google powers failed on this one. It doesn't help that there is a separate forum for every damn model of BMW. This is not a model-specific problem. Hopefully I can help others.

Some photos:





































It might actually have just needed the calibration all along. I tried a few things, and I ran through one of the trouble-shooters, which came back saying that I needed to run the stepper motor tests because something had failed and I think that was the the calibration that failed.. but I would recommend the next person try the calibration directly (from that screen above) first before dismantling.