Heater / Air con noises behind dash?

[Deltor]

I have owned a 1989 535i Sport for a couple of months, and over the weekend ther was a clunk and slight bang from behind the dash - sounded like something becoming disconnected and falling down.
Since then, there has be a constant sound ike a motor running from behind the dash, similar to the air flaps closing when you turn the ignition off, but a constant noise as long as the ignition is on.
I can't see anything obvious, but suspect I will have to attack it from the engine bay.
Is this something anyone else has come across?

[A1BMW535iSport]

have something similar on mine,
should there be any whirring noises with the ignition on??

Matt

[netmgr]

clunk and a bang, sounds like u hit a chicken...

switch the heating on full...if u smell chicken then you gota remove the dash and buy another one..

[Deltor]

Well I checked.. and no chicken.
I hate to be pedantic, but the car was stationary in my driveway at the time, so technically speaking, the chicken would have had to hit me, and I think I may have noticed... :o)

[Bill R.]

adv (windshield wiper pressure control) This happened to one of our longtime posters Quentin, or you may be able to tell if its the adv by placing your hand on the drivers side wiper where the wiper arm attaches to the shaft with the key on... if you can feel that something is running internally then its a broken adv

I have owned a 1989 535i Sport for a couple of months, and over the weekend ther was a clunk and slight bang from behind the dash - sounded like something becoming disconnected and falling down.
Since then, there has be a constant sound ike a motor running from behind the dash, similar to the air flaps closing when you turn the ignition off, but a constant noise as long as the ignition is on.
I can't see anything obvious, but suspect I will have to attack it from the engine bay.
Is this something anyone else has come across?

[Deltor]

Thanks for the advice Bill, having pulled fuses I managed to narrow it down to the blower motor (fuse 19).
I have no doubts that it's a complete pig to get at and try to repair whatever has happened in there. I presume the prescripbed route is to remove the header / expansion tank and attack through the firewall from the engine bay?
Any advice gratefully accepted..

[JonE]

Does this noise go away when you shut the fan switch off? Does it also go away when the fan position is on #4?

[Deltor]

The noise is present even when the fan switch is off, although there is so much noise from the fan on setting 4, that's it's hard to tell.
Currently (and before the 'problem') the fan switch seemed to do very little between 'off' and 2, with the fan only seeming to kick in at settings 3 and 4.
I suspect it may be time to change out the temperature regulator (in this case the 'sword' type) and perhaps the fan switch, although I'm sure this won't cure the new problem...

[JonE]

When my sword was failing it would intermittently make a low frequency humming/vibration sound and I would get very little air movement from the fan on speeds 1,2,3. It would blow very well on position 4. The noise would go away with fan switch off, though. Perhaps these swords fail in numerous ways with a variety of symptoms. Anyway, did you check Bruno's site for sword replacement instructions?