Rear Window Defroster Kills FM Reception

[Fifty150hs]

I did a search and couldn't find anything on this weird situation. I was listening to radio on FM band and had to turn on rear window defroster. When I did it killed the FM reception. Turned it off, reception came back. Turned it on, no reception again. Has anyone else experienced this or have any idea as to cause?

[80stech]

That sounds like a loose connection or bad ground somewhere by the back window.

[Fifty150hs]

Originally Posted by 80stech

That sounds like a loose connection or bad ground somewhere by the back window.

I didn't mention it doesn't affect the AM reception. Wouldn't a loose connection or bad ground cause the same problem with AM as well?

[80stech]

No, and you have to start somewhere.

[Fifty150hs]

Originally Posted by 80stech

No, and you have to start somewhere.

OK. A troubleshooting I will go.

[jljljl]

Wow,
I have the same problem!
I use a bluetooth receiver to listen to my songs on my phone and when I use the rear defroster, so much static comes on! Not all FM stations get the static when I use the defroster though.

Hopefully someone can chime in on a solution

[bmwman528e]

That happened on my e53 as well and just lived with it. I'd be interested to know what caused it.

[80stech]

I think Quicksilver has done one of his awsome posts that shows the antenna grids and how they work on another thread, Maybe if he is watching he could work his magic again

[Qsilver7]

AM/FM1/FM2 don't all use the same antennas...and there's also two different amps for the different RF antennas. You also have the remote key's antenna incorporated into the mix as well.

The BMW sedan's antennas are incorporated into the rear windshield along with the defrost grid. The Tourings and SAV's have antennas in the rear left cargo window as well as the rear window in the tailgate:

{sedans}






{Tourings & SAVs have antennas in side & rear windows and amps in D pillar and/or above tailgate}






{there's also suppression filters (see #7 in diagram below)...click link for specific part nbrs/names of components in diagram below}

Single parts f antenna-diversity | BMW X5 E53 X5 4.4i N62 USA

[80stech]