Vent System Conundrum

[h82crash]

I have a new-to-me 95 M3. I also have a 93 325is. Both have the same knob control panel.

In the 325, when I turn the knurled wheel to red, it makes the air in the vents warm...that's all. In the M3, when I turn the wheel to red, the air goes warm, but also the flow to the center dash vent is cut like 90%.

I read the owners manual for the M3 and apparently that is the intended way it functions. Did it change from 93 to 95?

Also, other issues with the M3.
1) The air flow at the foot well vents is almost non existent when set to foot well, or any other setting on the dial.

2) Air always flows out the defroster vents, except for one little position on the dial, like 2 clicks down from the foot well setting. Flap issues? Control knob issues?

3) I am wondering if I can get the M3 to function like the 325, which would be preferred.

I guess I'm looking at tearing into the dash to address these issues.

Can others tell me how their red/blue knurled wheel affects their vent operation?

[shogun]

Copy moved to E36 M3 forum

[h82crash]

So, no one has a red/blue wheel that works or wants to tell me how it works in their car?

[John in Houston]

The center vent assembly in the E36 has a blue cable that comes off of it and runs down towards the driver's side footwell. That cable assembly attaches to a blend door. My thought is that the cable may be damaged, kinked, maybe even disconnected. Might be worth pulling off the knee bolster under the steering wheel (and the associated metal plate) and see what that cable is doing when you rotate the dial. When I bought my M3/4/5, the center vent had some missing blades and the 'hot/cold' dial worked kinda like you said with lackluster results. New vent assembly remedied my issue (and gave me all the blades back).

ECS Tuning Vent

[h82crash]

Thank you. So, the wheel is supposed to reduce flow to the face vent when you turn it to red, interesting. I guess I need to explore more on the blend door and diverter door operations.

[Mless5]

I have a spare vent cable kicking about I could throw in the mail if that's what you end up needing. PM me if you do.

[h82crash]

Thanks, I don't think I'll need it. I think POs have messed with thing in the vent system and just didn't replace them correctly. Have to open everything up to replace the heater core, so I'll evaluate. Just think its weird that air is always flowing out the defroster except for one spot on the dial and feel hardly anything out the foot wells. Bad vent door seals, controller out of sync with the indicator markings is my speculation.