[tom86]

Hi All.

I replaced the blower fan on my newly purchased 2007 325i because the old fan wasn't spinning all all. Now with the new fan in place it's running consistently. I'm not 100% sure if this is due to the battery being too flat as its been sitting a while.

If its not to do with the battery, does anyone know exactly what else it could be? (considering its a brand new fan)

Tom P

[gbalthrop]

There is an Engine Fan (cools radiator & A/C Condenser) and a Blower Motor (Blows interior air). Each has an attached control module or "Final Resistor", and we can't tell from your description exactly what you replaced.

Whatever is "constantly running", it is NOT caused by the battery. Time to learn a bit about that part of your vehicle's electrical system.

Questions:
1) What are Last-7 Characters of your VIN (so we can provide ISTA wiring diagrams)?
2) Photo/ Location/ Parts link for New Part(s)?
3) Does "Blower Fan" shut off ~ 10 minutes AFTER you turn off engine & remove Key?
4) Do you have a simple Multimeter (~ $10US)?
George

[tcphoto]

My old E46 started developing a similar issue, the engine fan blew at top speed, I ordered a FSR module and pulled the fuse when I parked the car to save the battery. When the part arrived, I installed it and the issue disappeared. I would suggest following gbalthrop advice and go from there. I also find that YouTube is a great resource for DIY projects so you don't waste time or money.

[tom86]

Hi George. I believe I replaced both the blower fan and module as the module was bolted to the new assembly. Ebay link to part I replaced https://www.ebay.com.au/itm/284752481830

Instructions I used to install new fan. https://www.pelicanparts.com/BMW/tec..._Replacing.htm

Vin number of my car WBAVB16000NE51686

I'll do some tests of when it shuts off (if ever) I'm charging the battery overnight

[tom86]

Originally Posted by tcphoto

My old E46 started developing a similar issue, the engine fan blew at top speed, I ordered a FSR module and pulled the fuse when I parked the car to save the battery. When the part arrived, I installed it and the issue disappeared. I would suggest following gbalthrop advice and go from there. I also find that YouTube is a great resource for DIY projects so you don't waste time or money.

I replaced the FSR module I believe its called the resister on the E90? and I threw out the old one cause I thought it was fucked. Oh no. Its possible my car doesn't like the eBay resister

[tom86]

Originally Posted by gbalthrop

Whatever is "constantly running", it is NOT caused by the battery.

On BMW's when there's not enough voltage supply to the computer everthing goes haywire in my experience

[tcphoto]

Originally Posted by tom86

I replaced the FSR module I believe its called the resister on the E90? and I threw out the old one cause I thought it was fucked. Oh no. Its possible my car doesn't like the eBay resister

Why would anyone buy a car part from eBay? There is no recourse if the part is not a quality part, dies after feedback is posted or counterfeit. I try to buy from the reputable online vendors like FCPEuro, ECSTuning or Pelican Parts.

[lookalikehuuh]

Originally Posted by tom86

Hi George. I believe I replaced both the blower fan and module as the module was bolted to the new assembly. Ebay link to part I replaced https://www.ebay.com.au/itm/284752481830

Its probably this trash eBay part that is causing the issue. Go get a legitimate OEM part from FCP, pelican parts or similar and the issue should resolve itself.

For the record aftermarket parts like this cause all sorts of electrical issues with BMW vehicles as they are poorly manufactured and calibrated. Ironically these trash parts can actually cause electrical issues with other components in the vehicle.

[gbalthrop]

Originally Posted by tom86

I believe I replaced both the blower fan and module as the module was bolted to the new assembly. Ebay link
to part I replaced https://www.ebay.com.au/itm/284752481830
Vin number of my car WBAVB16000NE51686

Originally Posted by tom86

I replaced the FSR module I believe its called the resister on the E90? and I threw out the old one cause
I thought it was fucked. Oh no. Its possible my car doesn't like the eBay resister

FSR = Final Stage Resistor. See attached ISTA ScreenPrint for wiring diagram of Blower Motor & FSR.
Test blower motor: Red wire from FSR to Motor = B+; Brown wire = Ground/(-). Disconnect FSR from motor to test.

Wiring at FSR Connector, X18722:
1) The "PWM_LUE" line, White/Brown Wire, at X18722/4 (Socket #4 of Connector X18722 at the FSR) is Speed Signal.
Voltage measured with DMM on that White/Brown wire, in reference to chassis ground, should vary w/Blower Speed
selected on the Climate Control Panel using Manual buttons to increase/decrease blower speed.

2) "30<67" Line, Red/Blue wire, X18722/2, is constant battery voltage (Terminal 30), from fuse F67 on JB Panel.

3) "31" Line, Brown wire, X18722/1 is Chassis Ground.

If you still have the original blower motor, see if it works when you apply 12V+ to Red wire & Ground to Brown wire.
If it does, your old FSR was bad. If it does NOT, then you threw away good FSR.

If the voltage in PWM (Pulse Width Modulated) Speed Signal wire (White/Brown) varies when blower speed changed
MANUALLY on Climate Control Panel using blower speed buttons, then your "newly-acquired" FSR is NFG.

Please let us know what you find.
George

[Captain Buumer]

Car electronics is one place where i don't go cheapest route possible.

Most of times i've ended up purchasing same item twice.

Most probably the old fan got stuck and needs some lubricative oil (motor doesn't have enougth force to move it).
I prolonged mine for couple of years (it was really rusty) this way and you could try this too - can continue using the original one. This can resurrect it for some time - worth a try.
If it doesn't work and moisture has ruined inside then possibly can swap the FSR (white module) from old fan assembly and see if the new fan accepts it.
Motor part shouldn't be that different, simple DC motor.
The white module part they probably cheaped out with and causes you problems like George mentioned.

The root cause for this problem:
Interior fan orientation is bad (sealed side is to the bottom), it collects moisture and eventually seizes up. Of course minor leaking window seal / Plastic cowl cracks & worn seal speed up this progress.
Probably will drill couple holes in sealed side fan assembly next time i have troubles with it since i get 4 seasons per year.

[tom86]

Thank you for all the help guys. Sorry for the late reply I had to source a battery charger. I have now charged the battery for 24 hours and the car is starting and the fan is turning on and off now as expected (when the OSD lights are out, fan turns off)

However, I am now seeing a "Steering Lock Fault" (a red symbol of a steering wheel with a lock on it). Im not sure if this is due to my battery now being able to produce enough amps or it has something to do with my very tight steering problem. (See https://www.e90post.com/forums/showt...1917315&page=2 )

Is it possible the lock solenoid could be stuck down causing the steering to be tight?

So far I've replaced the power steering pump, reservoir and fluid

[Captain Buumer]

Read the fault code and get it fixed asap.

You'd eventually be unable to start the engine.

[tom86]

I was able to clear the fault using the BMW software clearing the elv counters link is

(if anyone runs into this)

The dead battery causes me a lot of issues. I'll remember in the future to never let it go flat and lever leave it disconnected too long. (I had it disconnected for several days while it was charging)