Blower Motor Controls bad? Blower Motor & FSR Replaced before.
 

***EDIT***
it was a freaking wire that worked its way loose somehow behind the HVAC controls pannel

Hi Guys.
I had my blower motor replaced with an OE part about 30 k kms ago. I have replaced Final Stage Resistors twice (when fan speed was not adjusting from controls yet air was still coming from system.
NOW I have a new issue.
None of the speeds work on the control panel. But the control panel lights up as normal and all buttons work, as normal and the speed goes up and down...but no fan motion occurs
I checked fuses 34,48 (A/C but just to be sure) & 64. All work.

I was removing the HVAC control unit from dashboard and when I removed the 3 wire black harness then big blue and nothing strange happened but when i unplugged the 8(ish) wire Black harness from the HVAC controller, the rear seats fans came on at mid speed, even tho their separate rear controls were set to off. Makes me wonder if there is a short or something wrong with HVAC controller

Has anyone had this hapen before during their repair and if so was it just a new HVAC control panel was required?
I'm realllllly hoping its not a Blower Motor that is required again.

Thanks for your time.

There are pins you can short on the hedgehog connector to jump start the blower to confirm it's functional. One of the few things I prefer on the e70 (my current car) is the change of the ludicrous blower location!

FYI I have it on very good authority you can change e53 blower though the radio opening in the dash.

Thanks for the reply.
I have heard, in the far past, too about being to pull the blower motor through the radio hole, if you have NAV (I don't).
And as for shorting the pins on the FSR, that's interesting.
I was gonna see if I could use INPA or DIS5.7 or Rheingold to see if I could trigger the blower motor too before anything serious gets repaired.
I was thinking of running to pick-n-pull to grab an HVAC controller from a 2005 4.8 (if this piece is still there) as a QUICK and hopefully cheap part swap (which I generally hate to throw parts at a problem).
I will look for the pins to short too, in case I can't activate the blower motor by computer.

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Sorry for your blower woes, Clockwork. Thankfully, I have not had to deal with blowers on 3 e53’s, but HAD to ask if 2005 4.8is in the nearby U-Pull-It happens to be imola red? My mirror cap had a whole bunch of paint just flake off the top edge this month, completely unprovoked! I’ve since scoured the marketplace and cannot find a replacement driver’s mirror cap! IF you were hitting that parts vehicle for HVAC stuff and IF it’s red…I would LOVE to know! Sorry for random intrusion to your thread! Thanks, and good luck on that blower!

When you say none of the speeds work on the control panel, is the panel display not changing the settings or it seems to be but the blower is doing nothing?

On final stage verify voltage (pin 2) and solid ground (pin 4). Then for test purposes you can short voltage and ground to blower motor.
*Pin 2 red/blue - Pin 5 red/green
*Pin 4 brown - Pin 1 black/green

https://bmwteka.com/wds/en/e53/d5f2388a

I once had a problem with blower which was caused by poor wire contact on final stage on the PWM control wire (pin 3) from IHKA to final stage. Cured by cleaning and some contact paste.

it is a black vehicle, unfortunately.
May be wasier to get yours painted OR wrapped!

great question!
The control panel lights up as normal and all buttons work, as normal and the speed goes up and down...but no fan motion occurs

Thanks VERY MUCH for this info. I'll try this tonight, for sure! Cheers.

Probably. Thanks for response!


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nuts, well its not a problem with the HVAC controls. I just ran to a pick-n-pull and grabbed the same controls only to connect it (after a good cleaning) to get same result. everything LOOKS like its working but no fan at all.
From what I've read, it seems the FSR dies and leaves the fan speed with on (one constant speed) or off.
Has anyone had a FSR die where it left the fan with no speed (like it was off)??
I'll jumper the pins tonight when i have time.
I, luckily, have a spare OE FSR, should I get that lucky and just need to replace that.
Thanks all