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My 2003 Tourer has very poor FM reception. I've replaced the FM antenna amp and the problem persists. Interestingly, when I raise the half-glass rear window reception is improved/good which leads me to think the connections to the window antenna are suspect - but I don't know if there is a separate antenna above the window or the car uses the rear heating element only. I'd heard these connections get corroded. Anyone managed to fix a similar problem? Very grateful for your help. Hugh.
 

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Check www.bmwgm5.com as I believe they have some info on the amps and antennas.

I cannot recall for sure, however, I believe the FM antenna in the touring may actually be in the rear side glass on the left side, but since you may have a right hand drive car, check both sides for the antenna, it should be on the side your antenna amplifier was located?? Printed on the glass like the rear defrost grille?? I believe it is visible if you look closely at the top portion of the glass??

There are problems with the wiring connections at this point as I recall?

Also do you have tint on your windows? This may be why you have an issue where when you lower a window your reception improves?
 

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Thanks for getting back to me so quickly - and for the links.
You are correct, there is a side window antenna which I believe is for AM radio (and the remote door locks?) but from what I've read the (Diversity) FM antenna is in the sill above the rear window. Getting to it to check the connections is tricky. Car is right hand drive with no window tints.
I wonder why BM made it so complicated when a sticking-up aerial would have done the trick! Thanks again. Hugh.
 

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I am dealing with this as well

Here is what I know. The AM antenna is a white ribbon strip that is inside the rear spoiler. it attaches to a powered amp also in the rear spoiler. also attached to that amp (which is part of the FM diversity system) is an FM antenna in the rear window....

so, from the amp in the rear spoiler/wing you have the one and only AM antenna and one of the two FM antennas...

a single cable then goes down into the rear left side to the main antenna amplifier (which has its own FM antenna - the left rear window)...

it is the antenna amp in the left rear that controls the diversity system and chooses which FM antenna to use

There is also a FM noise suppression unit in the roof near where the bee sting antenna is located (btw - the bee sting is for the old analog cell phones)

I am testing a non-BMW antenna (that I have wired into the BMW wiring) and so far the reception is MUCH better, but not as good as my sedan
 

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the other problem that tourings deal with, that sedans and coupes do not (as much) - if you have a Class D amp (subwoofer) - Class D actually works by switching its system on and off (frequency)- creating FM (frequency modulation) waves
 

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Thank you 33i ZHP.
I'm taking the car in to a vehicle electrics company on Monday armed with the information you've given me.
I already tried changing the main antenna amplifier (left rear) so I'm pretty sure that works. As I get good reception when I open the rear half-door, my sense is it's a connection problem to the rear window FM antenna (as AM works fine).
Boy, it's a complicated system. Thanks again, Hugh.
 
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