'94 540i antena/radio reception

[Matias]

Hi guys. My 540 has terrible radio reception and even my cd changer (pioneer) mounted in the trunk from doesn't sound 100% clear (I realize both problems are the same). I have this very silly question then: where is the antena in this car? How can I check if it has any problem?
What I see when playing a CD for instance is that under the frequency (89.5), the "ST" comes and goes and when its lid the radio makes this weird sound (kind of "laser sound" in a bad sci-fi movie).

Any ideas?

Thanks!!

[Tiger]

Antennae is located in the rear glass... the main problem is most people don't wire up the antennae power when switching to aftermarket head... because the antennae uses amplifier too... the white wire on the BMW harness.

[Matias]

Thanks, so what I need to do (besides running my spell checker more frequently) is to give power to the antennae via the white wire? right?


Antennae is located in the rear glass... the main problem is most people don't wire up the antennae power when switching to aftermarket head... because the antennae uses amplifier too... the white wire on the BMW harness.

[Tiger]

augh... it has been a long time... look... in any case, you must hook up your blue wire on your head unit to the bmw antennae wire in the bmw harness... The white wire on the antennae wire is one thing I forgot what it do...

If you got the aftermarket plug and play adapter to hook up to your BMW harness, then hook up that blue wire. If not, then you have to figure it out... I believe Bentley manual does decipher it for you.

[Matias]

Thanks again. I took a look in the trunk and this is what I found:
there's a black cable connected to the "antenna" jack of the Pioneer. I tried to follow that cable but as far as I got was just behind the driver's seat (parallel to the door). Do you think I have to remove the radio from the dashboard to find where that cable goes?

[Tiger]

The antennae amplifier is located in rear parcel shelf as far as I know. The connection I meant is at your head unit in dash.

[Matias]

Do you know how to remove the radio from the dash? I found two small holes at either side of the radio's front but I'm not sure what to do.

[Tiger]

U have factory radio or not?

[Matias]

yes, it's the original radio

[Tiger]

There is two doors in front... They tilt to the side like a door. It take a special screwdriver to take it out but everyone has pretty good luck with allen key to remove it. Once you take it out, you will notice that there are two antennae connection... one right above another... and one is tiny compared to the other...

It is most likely to be connected. I installed one FM changer long long time ago... but If I recall correctly, it does connect to the factory antennae and then they have one of its own that you will connect to your factory radio.

The controller must be near that cd changer display. Make sure this is connected correctly, The smaller antennae wire MUST be connected.

[Matias]

Thanks! I'll give it a shot and let you know how it goes.

[Matias]

what I found is this, to the radio's antennae connector there's 1 cable that comes from a small metalic box (aprox 1"x1"x1/2"). That box has 2 more cables, one looks just like the one that goes to the radio and the other, not as thick, seems to be from the CD changer. Does anything seem to be missing there?

Thanks!

[Tiger]

You really need to check with the manual for that changer... Like I said... there are two antennae connection for BMW radio... one above another... Both must be connected.