No air coming through my vents on my 91 318is

[tmacbmw74]

Ok so I was going to change out my blower motor since no air was coming out my vents. I removed the blower motor cover to make sure it didn't work but it actually did work and was spinning when system turned on. I tried the different flow speeds but it didn't change the speed of the blower motor. So I assume the resistor is bad as well. The blower motor is wired correctly and not installed backwards. The cables that actuate the flaps on the left and right side of the blower motor broke off from where they connect to the the lower recirc flaps that work in conjunction with the upper outside air flaps. I removed the lower recirc flaps and have the outside air flaps temporarily closed for recirc air only. Still no air is coming through my vents. All my zone functions work as I can see each cable moving when I slide the positioner for each area (windshield, dash vents, and leg vents. Is there anything that could be preventing air from coming through the vents? Is there another main vent that's shut near the heater core area I'm not seeing? Any help would be appreciated

[tmacbmw74]

Bump

[jeffnhiscars]

a mouse built a nest in your vents

[tmacbmw74]

a mouse built a nest in your vents

I've replaced the blower motor and watched in spin. I ordered a new blower motor resistor and need to install but even when it spins still no air comes out the interior vents


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[jeffnhiscars]

I've replaced the blower motor and watched in spin. I ordered a new blower motor resistor and need to install but even when it spins still no air comes out the interior vents


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you said that. Im suggesting your vents are blocked

[tmacbmw74]

you said that. Im suggesting your vents are blocked

Not sure how to access or get inside of them without pulling the dash. I've pulled everything but the dash and operated everything and seeing the vent motors work/move


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[Das Delfin]

if you feel like pulling your blower motor again you can then take out the plastic box it sits in. It's held in place by two nuts on either side. Once this is out you'll see the a/c evaporator. Might be tricky to get out without removing a few bolts securing the heater box in place down by the ash tray. Which involves removal of the center console ;)

Another angle is if you remove the glove box and have your aircon deactivated you can remove the a/c evaporator and slide it out to get a view

There is a main vent that shuts off hot air to the center mid level vents when the mid or low level sliders are not at full hot. But in either position it will still allow air flow. Maybe this piece is jammed? You should hear a solid "clunk" when opening/closing the middle slider.

if you're not getting any flow at all levels the problem is probably right next to your blower motor. I would try removing that and its box and see if something is weird with your evaporator

[Das Delfin]

here's a diagram showing a smplified cutaway view of what goes on inside the heater box



If you have the time, taking the dash out, removing the heater box, and allowing yourself the space to disassemble it on a work bench would be the most thorough way of solving this

[tmacbmw74]

here's a diagram showing a smplified cutaway view of what goes on inside the heater box



If you have the time, taking the dash out, removing the heater box, and allowing yourself the space to disassemble it on a work bench would be the most thorough way of solving this

Thanks for that info and diagram that sounds like that might be my problem I will try that next


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[jeffnhiscars]

If you remove the cluster, center console, glove box, radio etc...all of which pales in comparison to removing the dash, you should be able to access most of the potential problems. You can also pull vent piping (at least behind the cluster).