# E39: Which antenna adapter do i need?



## hans747 (Mar 28, 2014)

Hi Everyone,

i posted this in the e39 forum, but the answers were inconclusive. But someone told me i should take the question to the audio forum. So here goes...

I'm installing a used Sony MEX BT3700u single-din head unit into my 2000 528i Wagon. It is replacing a stock non-DSP Business Cassette head unit. Which antenna adapter will I need to get a decent radio signal? As you guys know, these cars have two antenna cables in the dash, and my Sony only has one place to plug in.

Here's the one that came with my wiring adapter:









Here is the one that Crutchfield told me i should get: 









Right now, I have the upper one in use, and I can barely get any radio stations to come in. FWIW: my car has always had what i consider sub-par radio reception, but nothing was as bad as what I've seen since installing the Sony stereo. I just want to know if need to use the other antenna plug. Or if i need to start looking into other potential problems.


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## jkwhar (Jun 12, 2016)

Reason why you're having a weak FM station is because the stock antenna is ampflied antenna. What I did was buy one of these amplified antenna and used it instead of the stock ones.

http://www.crutchfield.com/p_12044U...35945&awat=pla&awnw=g&awcr=47668963945&awdv=c


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## [email protected] (Aug 12, 2016)

hans 747 - does the adapter pictured on top that you currently have in your car actually plug into the factory antenna cable behind the dash? If so, also make sure you are powering the antenna control wire, which should be solid blue if you used a harness. Your car does have an amplified antenna, but it doesn't get its power over the antenna lead like VW and Audis do. The antenna module is behind the driver's side C-Pillar trim should you need to get to it in order to test that it's getting voltage.

Likely it's simply not being activated by the new radio via the blue wire. 

Let me know what you find!


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## hans747 (Mar 28, 2014)

Yes, it did fit on one of the antenna wires, but reception was awful. I ordered the other one (second pic) and hooked up the other antenna. Works great now!


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