BMW M5 Forum and M6 Forums banner

1 - 9 of 9 Posts

·
Registered
Joined
·
327 Posts
Discussion Starter #1
When my wife was riding in my new M5 for the first time the other day, she heard what sounds like a faint periodic cricket chirp coming from behind the dash in the center area. It is not proportional to engine or road speed, and the only time it seemed to go away was when I shut down the vent fan system completely. It seemed to chirp about once every second.

Could it be the little fan that circulated cabin air to measure cabin temp inside the heating/AC control panel?

Has anyone heard something like this?
 

·
Registered
Joined
·
6,517 Posts
It's the blower motor. And it will turn into a constant chirp over time. Sadly, replacing the blower motor (the cure) requires you remove almost the entire instrument panel.

d-
 

·
Registered
Joined
·
148 Posts

·
Registered
Joined
·
327 Posts
Discussion Starter #6 (Edited)
I kind of agree with the assessments that it's probably something in blower system, but I don't think it's the main blower.

I was wrong in the original post because it's still there with the blower off. That's why I thought it might be the little cabin temp sensing fan (the one in the panel that draws in cabin air to sense it's temperature).

The chirp is very faint (I couldn't hear it from the driver's seat, but my wife could with her ear near the nav unit).

It is a single short chip followed by about a second of silence (chip - pause 1 sec - chip - pause 1 sec - chirp - etc.).
 

·
Registered
Joined
·
622 Posts
This doesn't fit his problem at all-controlling the blower speed isn't the problem. The problem is a chirping sound from the dash area, which is probably-as others have mentioned-the blower fan physically making the noise.
MY FSU was changed by the dealer -low and high speed chirping gone! the FSU regulates the blower/fan action. If the FSU is sending "bad" signals to the blower it does fit his problem...Hmmm.
 

·
Registered
Joined
·
65 Posts
I too have this 'chirping' sound behind my dash and it seems pretty obvious (to me at least) that it is the blower as it only appears when the blower is on (when off it goes away) and only at low speeds.. as soon as it gets above 3-4 'bars', the noise goes away. Or could this actually be the FSU effecting this somehow?
 

·
Registered
Joined
·
148 Posts
MY FSU was changed by the dealer -low and high speed chirping gone! the FSU regulates the blower/fan action. If the FSU is sending "bad" signals to the blower it does fit his problem...Hmmm.
Interesting-I will have to remember that for future reference. Thanks for pointing that out.
 
1 - 9 of 9 Posts
Top