Mercedes-Benz Forum banner

1 - 13 of 13 Posts

·
Registered
2005 s500 4Matic
Joined
·
251 Posts
Discussion Starter #1
Hi All,

The radio reception on my 2005 s500 has given me issues since I purchased it 2 years ago. While the FM stations do work...if I drive under a small under pass....I loss the sound or get static and once I drive pass it..the sound comes right back. Even more concerning...I get no AM reception at all.
I had tint on all windows and have removed it recently..no more tint on windows. I dropped the headliner to check that the amplifier is connected and it seems to be fine. I have no way of testing if the original amplifier is working though. Is there a way to determine if it is? I have read the encyclopedia but unable to find a way of determining what could be causing this poor FM and no AM reception. I also pulled the amplifier fuse...#60 but no luck.
Has anyone experienced this and if so...what was the solution?

Should I just replace the amplifier with a used one and test it that way?

Thanks for all your help
Rick
 

·
W220 Moderator
2006 S 500
Joined
·
1,133 Posts
The amplifier filters out the signals coming from the rear window antennas, selectively amplifies them and sends them out via coax cable to their respective control modules. For AM/FM/TV they go to the Radio or COMAND. For Remote Unlock the key fob signal goes to Overhead Control Panel Control Module.

Some basic troubleshooting ideas:

Some reception, but its pretty weak---- That would indicate that COMAND / radio and antennas are working, but the amplifier isnt passing a strong enough signal. That MAY be due to bad amplifier, poor contact between antenna and amplifier or having a metallic tint applied to the rear window glass. The in glass antennas don’t have a “hardwired” connection to the amplifier. Note the small contact points at the end of each of the arms. That’s what connects to the appropriate antennas in the back glass. (Shown upside down). Anytime you have a “touch” connection you can have gunk ( for lack of a better term ) build up that can degrade that connection.



No reception at all, including key fob unlock ---- No voltage getting to amplifier (check fuse 61 in rear fuse box) means no connection from amplifier to antennas or amplifier has suffered a total meltdown.
 

·
Registered
2005 s500 4Matic
Joined
·
251 Posts
Discussion Starter #3
Hi Ex FEd

Thanks for the quick reply.
I read this article in the encyclopedia and while I believe my problem may be with the antenna amplifier....I find it odd that I get no AM reception at all and with FM...it seems ok unless I drive under even the smallest under pass or drive too far from a local station. My key fob seems to work fine in locking and unlocking the door.
I may just replace the antenna amp with a new one....just not too sure on how to remove the headliner to get to wires. I know the grab handles need to come off as well as the corner rear covers..but there seems to be a rivet holding the ends of the head liner to a bracket right by the rear window. Not sure if that needs to be drilled out or if I am missing something. It seems to be right next to the side window air bag activator.

If you have any insight...please advise.

Thanks again for all your help

Rick
 

·
Registered
S500 4Matic 2005
Joined
·
877 Posts
Hi Ex FEd

Thanks for the quick reply.
I read this article in the encyclopedia and while I believe my problem may be with the antenna amplifier....I find it odd that I get no AM reception at all and with FM...it seems ok unless I drive under even the smallest under pass or drive too far from a local station. My key fob seems to work fine in locking and unlocking the door.
I may just replace the antenna amp with a new one....just not too sure on how to remove the headliner to get to wires. I know the grab handles need to come off as well as the corner rear covers..but there seems to be a rivet holding the ends of the head liner to a bracket right by the rear window. Not sure if that needs to be drilled out or if I am missing something. It seems to be right next to the side window air bag activator.

If you have any insight...please advise.

Thanks again for all your help

Rick
Rick,

You do have to drill the rivets out. It's one on each side.
 

·
W220 Moderator
2006 S 500
Joined
·
1,133 Posts
Thanks Doni01 I was going to say there are Velcro pads. Was NOT aware there were rivets too.
 

·
Registered
2005 s500 4Matic
Joined
·
251 Posts
Discussion Starter #6
Thanks guys,

I ordered a used antenna amplifier from a 2000 s430 on Ebay. While I'm still not certain if the amplifier is the reason for my weak FM reception and zero AM reception, based on the threads I've read...the antenna amplifier is most likely the culprit. If there is any one else that has had these symptoms..please let me know how you resolved it.

Thanks
Rick
 

·
Registered
2005 s500 4Matic
Joined
·
251 Posts
Discussion Starter #7
Hi All,

I wanted to report the out come of replacing the antenna amplifier above the headliner. My original issue was with zero AM reception and poor FM reception when driving under even the slightest over pass.
I ordered a used unit from Ebay....same part number and I removed the window tint from the back window. I also cleaned the contacts with rubbing alcohol. While I noticed a VERY slight improvement in FM reception....I still have NO AM reception at all and still experience loss of FM signal when driving under an over pass. Has anyone else had this issue? If so please shed some light on the possible causes.
The antenna that sits on top of the back glass is missing but from researching the encyclopedia..it seems that is more for cell phone and emergency signal.

I have not removed the radio to check the wiring...but the fact that I do get sound from the FM stations at all probably means the antenna is plugged correctly into the back of the radio.
Is there a way to add a FM signal booster?? Its also odd that the AM stations do not come in at all.

Thanks for any advice

Rick
 

·
Registered
2005 s500 4Matic
Joined
·
251 Posts
Discussion Starter #9
Hi Wally,

Thanks for the clarification.
Even after checking fuses 62 and 64 to verify that the antenna amplifier is getting power, I am still having the same issue. No AM radio reception and limited FM.
I have already replaced my overhead antenna with another used from Ebay too. Any other suggestions as to what could be causing this poor radio reception?

Thanks again for your help
Rick
 

·
Registered
2005 s500 4Matic
Joined
·
251 Posts
Discussion Starter #10
Hi All,

My saga continues. I still have no AM radio reception and while the FM stations do come in...they are spotty and especially when driving under an overpass.
I have replaced the overhead antenna amplifier with a used one..I have cleaned the contacts wit alcohol and checked fuses 60 62 and 64. I have also removed the radio to make sure the wires were plugged in. I believe I have the version with only 1 harness and no antenna leads going to the command. I have removed all tints from the car but still no AM reception. Does anyone have any words of advice on what to trouble shoot next? I have removed the panels from the truck but do see any wires unplugged. IS it possible the built in amplifier on the used unit is also dead and if so wouldn't the FM stations not come in either?

Thanks again for any advice.
Rick
 

·
W220 Moderator
2006 S 500
Joined
·
1,133 Posts
AGW ( Audio Gate Way ) should be doing the actual FM/AM/WX tuning. That was a change that occurred at the time MOST replaced D2B.

Might take a look at it and see if a connector may have drifted off, or trace the coax where able to see if its been pinched.

Pic is Warren's (Skylaw) , The Great Documentor of All Things In the Trunk



If you cant get to a STAR machine to have the AGW checked out.. a replacement is running about $200USD on E-Bay.

Or, for about the same amount, maybe less,.. take a trip to dealership/indoe with STAR and have the entire system trouble shot and printed out.
 

·
Registered
2005 s500 4Matic
Joined
·
251 Posts
Discussion Starter #12
Hi Ex Fed,


That was great advice. I took your advice and located theaudio gateway in the trunk. All the wires were in place and even when I started playing with the wires to see if there was a broken connection...I still did not get any AM reception.
Of course that doesn't mean that its working 100%. Im not sure how to determine whether or not the internals of the AGW are shot. I guess only STAR can help with that.

Ebay does have used units for about $200 Im just not sure what the expected life is of these units and whether its even the AGW causing my lack of AM reception. The FM channels work but spotty.

I don't believe theres any other component that would control or amplifier the radio signals. I may just bite the bullet and order the ebay unit and take my chances.

Thanks again for the solid advice...I wasn't sure what my next move should be.

Rick
 

·
Registered
Joined
·
1 Posts
I recently had a similar poor radio reception problem with 2006 S430. turned out to be loose plug on the antenna above the headliner on passenger side rear. I had noticed that some days reception was good and other times very poor and once when hitting a bump it changed. remove pass side rear sale panel and grab handle, drill out headliner rivet and as soon as I touched the flat (power) plug the reception improved. I found that not pushing it back on fully made the contact better so hopefully this fix lasts
 
1 - 13 of 13 Posts
Top