saer1one

My buddy recently had an Alpine head unit installed in his 2002 c240.. So they wired every speaker from the rear to the new head unit since he has the BOSE system and wont be able to use the BOSE stock amp.. They gave it back to him the other day but the radio doesn't have any reception (am/fm), the shop told him that he would need an antenna amplifier.. I know that the w203 has the antenna amplifier behind the headliner at the back window.. So my question is, is the stock antenna amplifier connected to the stock BOSE amp..? And is that the reason he has no reception since the amp isn't being used anymore.. Or does he really need an aftermarket antenna amplifier to be able to listen to the radio on his aftermarket stereo..? I did search the forum but could not find an answer, any advise is greatly appreciated.. thanks in advance..

nrg_mike

Since it's an aftermarket head unit, make sure his antenna is plugged into the back of the new head unit properly. You may need a VW adapter to adapt the antenna to the new HU. Other issues may include the rear SAM or the HU itself. It'd not a bad idea to check FM sensitivity. Smaller values are better - they indicate an ability to pick up weaker stations. Expressed in decibel femtowatts (dBf)

OverDrive

No No.... As along as the antenna is plug into the headunit your fine for most of the wiring.... What has happen now is the Radio antenna is not powered...(You don't need their so called amp) All they need to do is take the Radio antenna power wire (Which is Solid black and on the same Connector as the Speaker Wire's output are) Cut and tap into the cigarette lighter 12+ Volt Power Cable. Once completed his reception will be restored (Please Disconnet the battery before doing this) You don't live that far from me (Marin County) I'll be happy to fix it if yall want to make the drive

saer1one

Thanks..!! so that explains it, i will tell him to call that ****ty shop of his to fix it.. thats crazy how many shops out there hire people who dont know **** and let them touch electronics they dont understand.. thanks again overdrive..

Grim001

Overdrive..there are two VW antenna adapters out there..the powered one and the non powered one....does your fix work with both? I have both and I get poor reception..so I am also looking for a solution. I just installed my HU so I will go back and see if this works for my vehicle (05' C240)

OverDrive

There should be 2 Wires, One that connects directly to your headunit which basically talks to the antenna to tell it what radio station you want (frequency) That should be non powered. Then theres the Black cable one thats part of the speaker connector which powers the antenna. On a W203 Mercedes headunit, When these are connected, everytime you turn on your radio, it sends power to the antenna. Since both of yalls are aftermarket... its doesn't have this feature so you need to bypass it to send power to it. (Easiest way would be tapping into the Cig Lighter as that powers up when your turn your car on) Hope that explains it with out being technical.

As for the new W203's I would have to look at them since I don't own a Facelift W203 (Theres 2 connectors for 2 separate antennas.... One for the Radio and one for the XM Radio

saer1one

overdrive, sorry for asking so many questions.. he wants to try it himself, where would he tap into the antenna power wire..? do you have a picture of that connector..? i browsed thru your thread (great job on the dash/command facelift!) but couldnt find anything.. if you could do me this favor as we have never seen what it looks like back there.. thanks..

hanknum

I just replaced my Bose headunit and amp with an aftermarket OEM style from a SL55. It took some modifications, but I got it cheap. Now I have Nav, DVD, and bluetooth. But I have very poor radio reception. I figure this is because I don't have power going to the antenna amp. I have a C320 wagon and the Bose amp was in the right rear. The connection to the amp was power, ground, 4 speakers + center, and three other wires (black, brown, & white). These wires lead up to the top of the hatch, where the antenna is. I've heard some say that I just need to provide +12V to the black wire...is that correct? If that is true, does anyone know what the brown and white wires go to? Do I need to ground either of the brown or white? I'm planning on putting a Soundstream low profile sub where the Bose amp was. Should fit fine.