[investmentbanker]

Hi

I have an issue where my AC randomly stops blowing for a second or 2 and then starts blowing again.

Originally I did some research and bought a new OEM AC Blower Motor Regulator or Resistor. That didn't fix it.

So then I was like scr*w it and bought a whole new OEM AC Blower Motor that also came with another new resistor. That didn't fix it either but it did blow a little better (probably because new motor) but it still randomly stops blowing sometimes.

I noticed it usually stops blowing (often but not always) during braking to a full stop or decelerating. Rarely it stops when driving consistently on the highway.

At this point I have no idea whats wrong. I'm wondering if the recall work I had done few years ago on the Positive Crankcase Ventilation (PCV) valve heater had anything to do with this but not sure.

Any help or ideas will be appreciated. Thanks!

[Cal122]

Does it also happen when the A/C is not in AUTO mode? (eg Fan speed set to high, only the middle vents enabled, auto recirculate off).

My '06 once in a while does this 1-2 second thing where it feels like it's changing modes and it stops blowing thru the vents, but the fan motor still appears to be running during this time. Doesn't seem to do it when I have MAX AC enabled. I'm guessing in my case it's one of the sensors in the AC system but haven't had a chance to dig into it more.

[smass]

I had this happen to me. The butt connector put in for the blower motor wiring recall had failed. I cut it out and put in a new butt connector. Test for voltage at the controller and you may see it goes low when the motor stops.

[investmentbanker]

Originally Posted by smass

I had this happen to me. The butt connector put in for the blower motor wiring recall had failed. I cut it out and put in a new butt connector. Test for voltage at the controller and you may see it goes low when the motor stops.

I think you are 100% correct. I knew it started after one of the recall repairs just can't remember which. Unfortunately I'm not super tech savvy or a pro mechanic so not sure I can do this one on my own.

Since BMW did this recall repair few years ago I think they'll probably charge me arm and leg to fix this.

[phils2]

Mine does this when the revs drop to idle and the voltage sort of "catches up". I've never looked into it though.

[gbalthrop]

Originally Posted by investmentbanker

... AC randomly stops blowing for a second or 2 and then starts blowing again...
noticed it usually stops blowing (often but not always) during braking to a full stop or decelerating...
I'm wondering if the recall work I had done few years ago on the Positive Crankcase Ventilation (PCV) valve heater
had anything to do with this but not sure...

Breather Heater Recall NOT related. OTHER 2017 recall: Blower Harness MAY be related. That required JB panel removal.
Assuming that your IHKA (Climate Control) Panel Light does NOT go off when blower cuts off, IHKA is fine & your
issue has to do with intermittent wiring fault in Blower wiring. First Suspect is White/Brown "Speed Signal" wire.

Attached is ISTA ScreenPrint for your 2006 325i Blower wiring. The momentary "cutoff" of blower may be due to:
1) "Inertia Effect" of slowing, due to wiring/connector issue (loose); OR
2) Reduced System Voltage @ decreased engine RPM; Test with Ignition ON, Engine Off. System Voltage ~ 12V vs. ~ 14V.
3) Intermittent wiring contact to rule out:
a) Speed Signal wire, White/Brown. Note that wire passes through the JBE (Junction Box Electronics) Module.
b) Voltage Supply, Red/Blue wire at X18722/2, at X11007/6, or Fuse F67 corroded spades/sockets.
c) Chassis Ground, Brown wire at X18722/1 or X490; be aware the recall required removal of JBE/ JB & new wiring
for Red/Blue Voltage Supply & Brown Chassis Ground, so HIGH likelihood of Tech Error in Recall if Blower cutoff AFTER.

If suggestions for testing with Multimeter are desired, please advise, & please let us know what you find.
George