SL350 (R230) Weak FM Signal following Head Unit Change

[WolfieS]

Hi, I have asked before, however … I’ve fitted an Alpine Head Unit into my 2005 SL350 (R230) where the FM reception is nowhere as good as the original. I received some excellent advice from ‘Richard’ concerning the feed to the Audio Gateway (thanks again), but I want to check whether I have done as much as I can. Advice requested as follows:

• After connecting a switched +12v feed to the Blue wire(s) entering the Audio Gateway, I was able to receive an FM signal at the Alpine Head Unit. Does this feed at the Audio Gateway also power the FM amplifiers hidden somewhere deep within the dash?
• If I need to separately power the FM amplifiers, is there an easy way to do this without dismantling much of the dash? IE, do 'blue' wire(s) appear somewhere easy to reach that I should apply +12v to?
• Would I need to individually power each amplifier (presume that there are 2 – one each side below the windscreen somewhere)? If so, same question concerning access as above.

Thanks in advance and hope that somebody can clarify/confirm whether I have done as much as I can to restore an FM audio signal from the in-windscreen antenna(s).

Regards

Wolfie Souter
Westbury, Wilts, UK

 

[crippo2]

Wolfie
I have, information, wiring pics & some photos if you still want them (I have removed the dashboard to replace the antennae pre-amps with some improvement) I think you have WIS. If so look at pe83.62-p2103-99ka as a good starting point and expand from there.
crippo2

 

[crippo2]

Wolfie
error Doc is pe83.62-p-2103-99ka.
crippo2

 

[richard]

The AGW has the radio tuners in and there feeds power to the two antenna amps when it is on.

That cable goes up the left wiring duct to one antenna amp, and then across to the other (which may mean it comes back down the duct and across, I can't remember) - so you could find it at the front of one of the wiring ducts. But if you power it somewhere else, don't forget to insulate it at the AGW plug !!

Getting to it at the antenna amps is impossible without removing the dash !!

The NTG2.5 antenna amps are more sensitive, but that would mean removing the dash and a phantom feed inserter as they are phantom fed.

Basically, the radio powers up the antenna amps in all modern cars, and in your car the radio was in the AGW so thats were the wire to power up the antenna amps is.

Richard

 

[richard]

ps, as you are going to have to take the radio out, and as you have already accesses the AGW why don't you just run a cable from the radio back to the AGW in the correct manner ? Its not much more to get the cable in the right place (or at least tucked up the side of the centre console where the carpet sits !!

R