AM/FM Connection to Aftermarket Head Unit?
 

I replaced my factory head unit (see below -- non Harmon Kardon) with an Alpine ILX-207. The only thing I'm not able to figure out is the AM/FM antenna connection. The factory head unit has a dual-white fakra input that I assumed was for AM/FM. However, there are only 3 Fakra connectors inside the dash: Green (attached to back-up camera), Mustard, and Blue. I tried the Mustand and Blue but there was no difference in reception. I can't figure where the AM/FM signal comes from.

Can someone how to get the AM/FM signal to connect the new headunit?
And, what is the color of the wire to power the antenna amp? I was told that it's the Gray with black stripe. Is that correct?

Thanks,
Peter
https://cimg0.ibsrv.net/gimg/www.mbw...588a8516bc.jpg
https://cimg1.ibsrv.net/gimg/www.mbw...043b82e17b.jpg

FWIW, I've been doing some experimenting and found that the AM/FM antenna is attached to the factory Sirius tuner that's located under the second row seat via the white dual fakra connector. The Sirius antenna also goes into that tuner via a blue fakra. Here's the interesting part: there's isn't an AM/FM or Sirius antenna that connects directly to the headunit. It seems that the head unit pulls the AM/FM and Sirius signal directly from the Sirius tuner.

I figured this out by reconnecting the factory head unit with just the main harness (did not connect the smaller harness or blue, mustard, or green fakra). I tuned to an FM station then unplugged the white dual fakra from the Sirius tuner in the 2nd row and lost all AM/FM service. I then tuned to Sirius, pulled the blue fakra and lost the Sirius service.

I then tried to feed the AM/FM signal directly to the aftermarket headunit by bypassing the Sirius tuner. I connected the dual white fakra in the 2nd row to the AM/FM input on the aftermarket head unit. I also attempted to power the antenna amplifier by connecting 12 volts from the head unit to the Gray/Black wire on the factory harness. Unfortunately, there was no improvement to AM/FM reception.

I'm about ready to give up and simply add a universal antenna to the new headunit. Does anyone have any other ideas on how to get the factory antenna to work with an aftermarket head unit?
https://lh3.googleusercontent.com/It...w1768-h1326-no

I have been doing some research on this as well, and I believe you discovered the same thing as I, not double white Fakra connection. What I discovered is there is a single Fakra connection (covered in a foam wrap) that gets converted over and the wire goes straight into the main connection block. I believe that to be the FM antenna wire. I have ordered an adaptor off amazon and I think that will solve the issue. You should be able to unplug the connection and plug it into the adaptor then on to your new head unit (if it has the double fakra). If it doesnt you'll need to convert it with a single male Fakra to a standard radio plug.


or this

Thanks for sharing! I hope I'm wrong but if it's the one I'm thinking, isn't that the cable that's connected to the Iphone adapter in the glove compartment?

No...that's an entirely different plug....I didnt even connect that plug to my new radio. The wire i am referring is connected to the main big block from the command center. Not sure if you can see it in the second picture...but it's the white single fakra cable with the foam around it.....it converts from Fakra to a wire that goes right to the main block.
https://cimg0.ibsrv.net/gimg/www.mbw...e3433ab908.jpg

https://cimg8.ibsrv.net/gimg/www.mbw...59abcdc3dd.jpg

Ok, I see what you mean now. Which wires is the fakra connected to?

My GL has two harnesses that were connected to the OEM head unit (see photos). Do you have the same two harnesses? My smaller one has a white fakra connected to the white and black wires. Is that the same one you're referring?


https://cimg5.ibsrv.net/gimg/www.mbw...f00e52e01f.jpg
https://cimg6.ibsrv.net/gimg/www.mbw...863f04ab72.jpg


https://cimg4.ibsrv.net/gimg/www.mbw...17dac58384.png

Thats correct, I am almost 95% sure the connector at the top (in your picture) is for the Ipod Interface. Its not even hooked up on my install now, and I am pretty sure I traced the wires back to the glove box. The bottom white Fakra is what I believe to be the FM antenna. I didnt even notice it the day when I did my install, since I was expecting to see a double fakra from the original command center. My new AVIN unit has a double Fakra for FM reception as well. I read on this string post 83 it might/should be the antenna

https://mbworld.org/forums/gl-class-...-2008-a-4.html

I have yet to take my radio back out to confirm. I have already ordered the adapter and I have a back up plan (a wired powered antenna) on the way, so Ill be covered either way. My plan would be to disconnect the white single Fakra and plug it into my new radio with the adapter cable I am waiting on to see if that solves the issue.

What year is your GL? Mine's a 2012. Do you have the same two harnesses that I do? I'm still not understanding which wire your fakra connects to?

In mine, the white fakra in my first photo connects the adapter in the glove compartment to the black and white wires in the smaller harness (as shown in the diagram).

how did you make out? im in the same boat. thx in advance

Hello

Were you able to locate the FM antenna, I do have same GL 2012 and struggling to get the FM signal

Thanks

I was able to buy a 15' Fakra cable that I ran from the new unit to the Siruis Radio tuner underneath the passenger driver side rear seat. Once i connected it up...FM reception works fantastic! Another member WaveyKat came up with the idea.

thanks for the reply, I did locate my SIRIUS HD Radio underneath the passenger , but did you connect the double white Fakra ? In my case my JVC KW-V940BW DVD Receiver contains only one Fakra ?

Yes....you connect one side of the double fakra that's goes into the Sirius tuner to the 15' fakra cable...then the other side to your head until antenna port. I'm pretty sure it doesn't matter which of the 2 sides you use...I chose the left side.

Sorry dont have any phone pics to share.....but if you do a search for the "Andriod Oreo 9" radio" you will find the thread with pictures

hello

I just tried the white FAKRA that was connected to another harness, same as suggested above. I had to search for it as it was deep inside. Connecting it to the Antenna in my aftermarket did give me a very good FM signal.

Also, my backup camera worked perfect with FAKRA to RCA adapter, but still I am missing the interrupt cable as my aftermarket device need it.

this is exactly what I was looking for. Thank you. Did you have to power the xm receiver to get the antenna to work?