e34 Fan System

[porterrico]

Hi everyone

i was just wondering if anyone could help me with a problem with my e34 (520i) fan system. the main blowers only blow cold air but the other two (under the screen and under the dash) blow warm air. i have no idea what i could be and i am freezin when i drive ....... HELP!!!!!!!!!!!!!!!!

THANKS JAMES

[shogun]

Hi James,

can you give us some more information on your system, such as with/without aircon,
how is the setting of each wheel at the control panel when this situation appears.

[Qsilver7]

do you have an owners manual? it so, it will help you understand the HVAC system...it has something called "stratified" air distribution. This allows you to blow hot/heated air to the floor and windshield...but also allows you direct warm or cooler air to your face (dash vents) to keep you alert of from becoming sleepy (hot air in the face can do that). The dash vents have another reostat controler (dial) in the middle of the center dashh vents...do you have that dial turned toward the "blue" dot...if so...then cool air is going to blow out of the dash vents. The "red" dot will allow you to select warmer/ air to blow out of the center vents. You may also want to shut off the vent at the rear of the center console...it only directs fresh air or cooled "conditioned" air to the rear passengers...rear passenger receive heated air thru the floor vents under the front seats.

(in case you don't have an owners manual)

When you read the owners manual...you'll see that, for heating, it suggests using sliders #1 and #3 (windshield & floor vents).

[ra_pro]

I may have the same problem. For me dial/control for the dash vents makes no difference . It always blows cold air whether it's on blue or red. What needs to be checked?

[Anthony (M5 in Calgary)]

I may have the same problem. For me dial/control for the dash vents makes no difference . It always blows cold air whether it's on blue or red. What needs to be checked?

There's a stepper motor that controls the temp of the upper vents. Its bracket is flimsy and breaks off due to the torque from the stepper motor. The motor then cycles out of its operating range due to the nature of the design. Temperature cannot be controlled at this point.

Here's an ugly but effective repair - viewed from inside the glove box area, directly behind the radio/OBC.

[porterrico]

Cheers for the help i managed to get it working thanks to you all helping me!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!! now i can take my coat off in the car ha ha

[Jay 535i]

Cheers for the help i managed to get it working thanks to you all helping me!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!! now i can take my coat off in the car ha ha

So, what was wrong?

Anthony, can you explain a little more what we're looking at there?

[VentoGT]

OK, reviving an old thread. Now that it is starting to get cold, I realize that my stratified air vent in the center is not working; it blows cold when I have the AC on and hot when I have the heat on but it only blows in conjunction to the temp dialled in, regardless of the warm/cold knob in the center of the dash.

On my e46, when I move this from warm to cold, there is some resistance. In the e34, the wheel gives no resistance at all. Could it be the stepper motor bracket issue? Thanks in advance.

[colo525i]

Hate to hijack this thread, but are the red and blue dots supposed to be lighted? i could have sworn they lit up when i first got the car.

[Yiorgos]

You mean these?



Never were lighted on my car...