Blower fan & direction problems

[fixit man]

Hi,

can anyone help me get an Idea how to fix this problem please ? I have a 2004 2.2L Z4 I bought it privately a month ago ...I noticed that the Cabin heater fan seems to have a mind of it's own If I put it at level 3 it will go up and down in speed throughout the journey.

The direction is also crazy, If i put it to windscreen it will do windscreen(80%) plus feet(10%) and vents(10%) and the same If I put it to feet only, it's up and down all over the place.

It has been for sale for quite a while and parked up so It's possible that the battery was flat..I know this may cause problems like this ??

Any help appreiciated :?

Fixit man

 

[BMWZ4MC]

Hi, and welcome!

There is a well known problem with those E46 BMWs that have climate control. If the final stage resistor (aka 'hedgehog') fails, it will lead to the exact symptoms you describe. It can also cause the heater fan to run on after the car is switched off, even when the ignition key has been removed. If the car is not driven for a while, this may lead to the battery going flat. The fan may run on too slowly to be heard, so you may not appreciate that it is doing so until you find the car will not start after a few days of not being used.

I don't know whether your 2.2 Z4 has the same climate control as the E46 BMW upon which ultimately all Z4s are based. My ///M definitely does not, but my E46 320d does. I would suggest looking into what system was used in the Z4 in 2004 - perhaps asking BMW themselves (they will know the problem).

Read the following article, it may help:

http://www.motormec.co.uk/aircon.pdf

Also, you can search the forum for similar problems: http://www.z4-forum.com/forum/viewtopic.php?f=3&t=6956 and even ask Incompatible how he solved the problem with his car!

Good luck!

 

[fixit man]

Hi BMWZ4MC,

thanks for the info. I will check it out, mine is a very simple system not like on the PDF link you attached..no a/c ! but it could be a similar problem aka Hedgehog.

Thanks
Fixit man

 

[cj10jeeper]

Final stage resistor is also a well known X5 problem. Mine went and did all the things you described and basically gave the system a mind of it's own. It would even start up whn the car was locked...

That would be my starting point, but I have to say that I don't even know if Zeds have one.

 

[fixit man]

Hi J10jeeper,

thanks, I must get a Haynes manual or something to see whats going on, I'll keep you posted ..thanks

 

[Lightning87]

did someone do this ?? as i'm probably next, i have the same symptoms since i bought the car.

now i'm looking fo a how to, as the only 1 i could find is the E46 one :
http://www.bimmerfest.com/forums/showthread.php?t=472392

so if anyone knows how.... please please tell me !

 

[KERMIT1970]

Hi, and welcome!

There is a well known problem with those E46 BMWs that have climate control. If the final stage resistor (aka 'hedgehog') fails, it will lead to the exact symptoms you describe. It can also cause the heater fan to run on after the car is switched off, even when the ignition key has been removed. If the car is not driven for a while, this may lead to the battery going flat. The fan may run on too slowly to be heard, so you may not appreciate that it is doing so until you find the car will not start after a few days of not being used.

I don't know whether your 2.2 Z4 has the same climate control as the E46 BMW upon which ultimately all Z4s are based. My ///M definitely does not, but my E46 320d does. I would suggest looking into what system was used in the Z4 in 2004 - perhaps asking BMW themselves (they will know the problem).

Read the following article, it may help:

http://www.motormec.co.uk/aircon.pdf

Also, you can search the forum for similar problems: http://www.z4-forum.com/forum/viewtopic.php?f=3&t=6956 and even ask Incompatible how he solved the problem with his car!

Good luck!

Sounds like the problem I had on my e46,new hedgehog fitted & problem fixed

 

[BMWZ4MC]

Unfortunately, I fitted a new hedgehog and my 320d still flattens its battery sometimes. The car can go unused for a fortnight and be fine, or on occasion the battery may go flat over a weekend :headbang:
I have a second battery and jump leads which I keep on the floor behind the driver's seat just in case. I think my problem related to an aftermarket head unit that was fitted by the previous owner.

 

[bcworkz]

The "Final Stage Resistor" location in Zeds is shown as N2 in this diagram. Presumably the RHD version is the mirror image.

It's amusing we still call it an FSR or hedgehog, it is much more than the simple wire wound resistors found in older systems from which the terms derive. The WDS actually now calls it a "Blower Output Stage". It is an electronic version of a FSR.

 

[fixit man]

Mine sorted it's self out, very rarely it does it again but only for a minute or two, so I'm not bothered :driving: