[AbbieMPLS]

My son's E90 stopped kicking any air from the system a few weeks ago. Before it completely stopped working, he said it would randomly adjust the air speed or just turn off. The IHKA appears to be working; we can adjust temp, adjust speed, and the rear defrost works. But even with the fan speed turned all the way up, or the defrost on, nothing comes out of any vents.

We have replaced the blower motor, blower final stage, fuses, and car battery. We have programmed the new battery to the car and confirmed it works. We tested the new blower motor directly before we installed and it worked, but hasn't worked since install. We also had the blower motor wiring harness replaced by BMW as part of a recall. We removed the air filter housing and I can see that the blower motor is not spinning.

I just took the car to BMW to have them recheck their work, as the issues started after they did the wiring harness replacement. They confirmed there is power to the motor and the fuses are good. They checked the harness and it works. They claim the blower motor doesn't work when they test it, which would mean it failed after we tested and installed it two days ago.

When we adjust the fan speed on the IHKA, it sounds like something wants to engage. There is a faint "click", but no air movement.

Any suggestions? It was -20 degrees here when this went out, and we need to fix it ASAP.

[gbalthrop]

Originally Posted by AbbieMPLS

... even with the fan speed turned all the way up, or the defrost on, nothing comes out of any vents. We have replaced the blower motor, blower final stage, fuses, and car battery.[Time to DIAGNOSE] ... We tested the new blower motor directly before we installed and it worked [Did you test OLD motor same way? IT probably works as well], but hasn't worked since install. We also had the blower motor wiring harness replaced by BMW as part of a recall... Any suggestions? It was -20 degrees here when this went out, and we need to fix it ASAP.

Obligatory RANT:
1) ASSuming the cause of YOUR issue is same as that of someone whose vehicle had SIMILAR symptoms SOMETIMES works for Mechanical Issues. It SELDOM works for Electrical Issues.

2) When dealing with Electrical Issues, "You can't tell the players without a program"! A Wiring Diagram is that "Program". In your case, BEFORE you incurred $$$ Expense, you SHOULD have:
a) asked for help HERE;
b) asked for ISTA Wiring Diagram & test suggestions using cheap ($10) DMM (Digital Multimeter);
c) while fault codes in IHKA or JBE Modules MAY aid in your Diagnosis, they are NOT mandatory; you CAN get those codes read FREE at local Advance Auto, AutoZone, etc.;
d) if you will answer questions below, WE CAN HELP!
Here endeth the RANT.

Questions:
1) What are Last-7 Characters of vehicle VIN? Many changes in 2007 Electrical System 3/1/2007 in middle of 2007 run.

2) Do you have a DMM? See links below to get one for $10 or less:
https://www.harborfreight.com/7-func...g_q=multimeter
https://www.amazon.com/s?k=digital+m..._ts-doa-p_3_26

3) Bonus Question, NOT mandatory: What Fault Codes are read in JBE (Junction Box Electronics) and IHKA (Climate Control) Modules?

With answers to those questions, we can walk you through some tests (DMM required) to determine WHY blower is NOT being "Activated" by the Climate Control Module. Based upon your description of events, first suspect is "Speed Signal" (PWM: Pulse Width Modulated) from IHKA Module to Blower Resistor, VIA the JBE Module. All MAY become clear when you see the ISTA wiring diagram I'll provide.

If the issue BEGAN when Dealer performed Blower Harness Recall, removal of JBE or JB connectors to do that Recall Procedure likely caused the issue.
George

[crashoverride]

The blower not working is often due to a failing battery. The fan will work intermittently another sign is the rear defroster not working occasionally as well.

But main question is why did you take the car home from dealership without them having gotten it working..??

[lordnikon]

It's not clear from your post who did the install. Did you do it yourself prior to taking the car in or did the dealer do the install?

If the dealer did the install, they should have warranty for their work done.

[gbalthrop]

Originally Posted by crashoverride

The blower not working is often due to a failing battery...

Please describe HOW a "failing battery" can (1) Start engine, and (2) cause Blower Motor NOT to operate when engine is running??

AFAIK, the Primary Purpose of the Battery is to Power the Starter to Start the Engine. I can't recall EVER seeing a case (in 60+ years of auto maintenance/repair ;-) where a battery that started an engine prevented operation of an accessory such as Blower Motor with engine running.

I am NOT attacking YOU. I AM attacking the "Myth" that the Battery is always the "First Suspect" when ANY type of electrical issue arises. That is almost always accompanied by the myth that BMW electrical systems/ batteries are somehow "DIFFERENT" from those used in other Makes.
George

[AbbieMPLS]

Great questions. When we had the wiring harness recall completed by BMW, the blower was working when we picked the car up. It would turn on, adjust speed, etc. However, we had very mild weather here, so it wasn't being used regularly. It was when the seasons changed and we were using the heater regularly that we noticed the intermittent fan operation.

Basically, we started by replacing parts we knew needed to be replaced and have now landed on a potential electrical issue. We did test the old blower motor first, and it did not work. We replaced both the motor and final stage together, as we assumed they'd both been installed at the same time (we've only had the car a little over a year). We also had the battery tested and it needed to be replaced. And of course, checked the fuses (did this first in hopes it could be that easy).

I read the codes and took the car to AutoZone to be certain I read them correctly, but nothing to do with the electrical system. There is a code for a cylinder 3 misfire that is being repaired next week, but nothing else.

I pulled the service manual and wiring diagrams and realized I had no idea where to start. I have a DMM, but would appreciate any suggestions for where to start. Thank you all!

[AbbieMPLS]

Originally Posted by gbalthrop

Obligatory RANT:
1) ASSuming the cause of YOUR issue is same as that of someone whose vehicle had SIMILAR symptoms SOMETIMES works for Mechanical Issues. It SELDOM works for Electrical Issues.

2) When dealing with Electrical Issues, "You can't tell the players without a program"! A Wiring Diagram is that "Program". In your case, BEFORE you incurred $$$ Expense, you SHOULD have:
a) asked for help HERE;
b) asked for ISTA Wiring Diagram & test suggestions using cheap ($10) DMM (Digital Multimeter);
c) while fault codes in IHKA or JBE Modules MAY aid in your Diagnosis, they are NOT mandatory; you CAN get those codes read FREE at local Advance Auto, AutoZone, etc.;
d) if you will answer questions below, WE CAN HELP!
Here endeth the RANT.

Questions:
1) What are Last-7 Characters of vehicle VIN? Many changes in 2007 Electrical System 3/1/2007 in middle of 2007 run.

2) Do you have a DMM? See links below to get one for $10 or less:
https://www.harborfreight.com/7-func...g_q=multimeter
https://www.amazon.com/s?k=digital+m..._ts-doa-p_3_26

3) Bonus Question, NOT mandatory: What Fault Codes are read in JBE (Junction Box Electronics) and IHKA (Climate Control) Modules?

With answers to those questions, we can walk you through some tests (DMM required) to determine WHY blower is NOT being "Activated" by the Climate Control Module. Based upon your description of events, first suspect is "Speed Signal" (PWM: Pulse Width Modulated) from IHKA Module to Blower Resistor, VIA the JBE Module. All MAY become clear when you see the ISTA wiring diagram I'll provide.

If the issue BEGAN when Dealer performed Blower Harness Recall, removal of JBE or JB connectors to do that Recall Procedure likely caused the issue.
George

To answer your questions, the last five are KX52440. It's my understanding the car is pre-3/07. We do have a DMM. And there were no codes associated with the JBE or IHKA when we had them checked. Thank you!

[gbalthrop]

Originally Posted by AbbieMPLS

To answer your questions, the last five are KX52440. It's my understanding the car is pre-3/07. We do have a
DMM. And there were no codes associated with the JBE or IHKA when we had them checked. Thank you!

ISTA ScreenPrints Attached:
Attached are ISTA ScreenPrints for your 9/2006 build 2007 328xi E90, showing Blower (M30) circuit, Location of Connector
View at Blower Resistor (X18722), Connector X14272 (Black), & Connector View, on JBE Module, below JB Fuse Panel
and Connector Location & View of X608 at rear of IHKA Module (X608).

Wiring & Tests:
A) Tests at Resistor Connector, X18722 (DIS-connected):
1) Voltage test at X18722/2, Red/Blue wire at Socket #2 of X18722 should show 12V+, battery or KL30 voltage, unswitched;
2) X18722/1, Brown wire, metal socket should have "continuity to chassis ground" or ~ 0 Ohms Resistance, with Red Meter
Probe contacting metal socket, and Black Meter Probe contacting Chassis Metal/ Ground.

Those 2 tests should have SAME result whether Ignition On or OFF. Next Test requires Ignition ON.

3) Ignition ON, IHKA Panel on/lighted, manual blower speed MAX (top stair step ;-):
a) Voltage at X18722/4, SMALL White/Brown wire, should be in 7.5V to 8.5V range, Red Meter Probe on X18722/4 & Black
Meter Probe contacting Chassis Ground.
b) Change Blower speed to Lowest Stair Step with Panel still lighted. Measure/ Record Voltage SAME way.

More Tests if Voltage in "3" Out-of-Range:
1) Disconnect JBE Connector X14272 (Black), and locate Socket #18 (end of row), White/Brown wire, coming from IHKA;
2) Repeat tests described in 3(a) & 3(b), measuring voltage at X14272/18. Record & Post Values;
3) While X14272 disconnected, carefully inspect pins & sockets at X14272/18 & /23 for corrosion or damage. This is
particularly applicable if there was large difference in Voltage Values at X14272/18 vs. X18722/4.

Please post your test values recorded in tests above, and we can either confirm you have found the problem, or
suggest additional steps (such as IHKA removal to check X608 connector). Remember that if issue BEGAN after Blower
Harness Recall performed (which required disconnection of JBE & JB connectors), we are expecting the
last tests above to identify the issue.

Test Blower Motor ONLY, On/Off, NO Speed Variation:
Test with blower installed or SECURED, as LOTS of Torque.
Apply 12V+ to Red Blower (M30) wire & Ground to Brown M30 wire.
Blower should operate at Top Speed.
George

[crashoverride]

Originally Posted by gbalthrop

Please describe HOW a "failing battery" can (1) Start engine, and (2) cause Blower Motor NOT to operate when engine is running??

AFAIK, the Primary Purpose of the Battery is to Power the Starter to Start the Engine. I can't recall EVER seeing a case (in 60+ years of auto maintenance/repair ;-) where a battery that started an engine prevented operation of an accessory such as Blower Motor with engine running.

I am NOT attacking YOU. I AM attacking the "Myth" that the Battery is always the "First Suspect" when ANY type of electrical issue arises. That is almost always accompanied by the myth that BMW electrical systems/ batteries are somehow "DIFFERENT" from those used in other Makes.
George

No attack taken... I take fault in your summary of the myth as not "Every" electrical problem.

But the blower fan and a questionable battery. This is a very real thing on this car and happens quite often as reported by multiple people. As a layman I can only go off of the very real world happenings of the gremlins I've come across in using the e90 on a daily basis.

I can throw out some ideas such as the computer values certain functions over others. Such as preserving the battery for starting, maintaining computers, lights and on down etc... I know the car has a battery level monitor that tries to keep enough juice in the battery for starting.


What occurred in the two times my battery needed replacing is I would be driving down the road the fans would blow then stop then blow some more then stop. I replaced the dang regulator at least three times thinking that was the issue. I also noticed sometimes the rear defroster worked or intermittently worked.
Finally I took the car to the dealership. They called me saying they were struggling to find a cause. I said hey I have a new battery I'm planning on installing in the trunk install that. they got a new correct battery installed and all my problems went away.

So I hear ya but with computers they can be programmed to make each car work differently.

[smass]

My blower motor just stopped working. I found low voltage when I back probed the wires at the regulator under load. The crimp connectors put in during the recall work were failing. A new crimp connector is working for now. In the future I am going to replace the entire harness as it is only at $11 part (61-11-8-714-661). Although removing the fuse box is not fun!

You may ask why I am not going back to the dealer to have this fixed for free. My car is in the final stages of an 8 speed swap and is not wired clean yet. I did take pictures and created an incident with NHTSA.