radio hiss....when heated rear window is switched on

[MSPORTBMW]

Hi there......just noticed this with the cooler weather.  04 x5 using the mk4 nav.

When im listening to a FM radio station and switch on the heated rear window, there is a hissing noise and you can no longer hear the radio.......switch window heater off and the music is back !!1

Any ideas?

Thanks

[petert]

I've had that in a previous BMW as well.  Was fixed under warranty but when i asked they said it was just a bad connection that they managed to clean up and improve reception.  (IIRC the rear window heating element doubled up as the radio antenna but I stand to be corrected...)
Peter T

[X5Sport]

You're right Peter, the element is also used as the aerial.  It is likely that a device preventing the heater element power getting to the radio is failing and you may be getting a 12v feed down the aerial which will cause reception issues.

Depending upon what options are fitted to the car there may be a 'diversity unit' in the aerial system and it could be this that's being affected, or the radio receiver itself.  If memory serves, there is also an aerial element on the near side rear quarter window too.

Richard

[rhinoman]

Any ideas where to start troubleshooting this as its happening to mine too.

[Horizon]

[quote="MSPORTBMW"]
Hi there......just noticed this with the cooler weather.  04 x5 using the mk4 nav.

When im listening to a FM radio station and switch on the heated rear window, there is a hissing noise and you can no longer hear the radio.......switch window heater off and the music is back !!1

Any ideas?
Had the same thing on my E60, very annoying, had to have the CD on until the window cleared, never did get to the bottom of it.



Thanks
[/quote]