BlackJacks

I have read a lot of issues with the Merc Radios and not found much in the way of explanation as to why the issues exist.
I have read everything from changing the Amplifier (hidden under an easy to remove head liner containing the "Red and Orange" reverse parking sensors on my E220 W212) to replacing the Command unit and rear windscreen.
I know my car had the rear screen replaced before I got it (as I found a couple or three, tiny bits of glass, in the car and boot (Trunk) when I cleaned it) and it had poor radio reception when I got it but I thought it just needed tuning in. To try to test something I unplugged the radio amplifier (near the reverse "Orange / Red" lights) under the roof panel. When disconnected there is no radio reception at all and the central locking also stopped.
When I reconnected the Amp the central locking worked again so I assume the Amp works.
So was wondering if a rear screen replacement could affect the radio reception.
I.E. Does the radio need resetting (and if so how) after a rear window change? Or is there a MB Radio Guy (or Girl) out there who might have done this before.
I just hate to leave my car with something not working.

I will try (if I can find one) another aerial and plug it into the Amplifier but it might take me a while to get one. If I get any joy (or Not) from that I will post it here.
Thanks in advance.
Jacks

Arrie

Which radio are you talking about? The antenna (shark fin) that you disconnected is for satellite radio. FM radio antenna is built in the rear window and if your issue is with the FM radio it may well be that it was poorly connected or something when the glass was replaced.

BlackJacks

Hi Arrie and thanks for the fast response. It is the FM part of the MB Radio that has the poor reception issue. The thing I disconnected was, I think, called the FM1 Aerial Amplifier.
Photo of similar item (this shows the wires as cut but I did not cut mine :-) ).
I did not touch the shark fin as I thought that was for the phone connection and I don't think I have Satellite Radio.
Many thanks for your advice on the window replacement connection as a possible issue. I will go and circuit test it.

This is the same as the one I removed. But not the one as I did not cut the cables :-)

BlackJacks

I've tried a Halfords powered Aerial and can't get to work. Next I took out the Command Nav box thing (Radio to me) and can't find the Aerial Lead. I was going to circuit test the cable from the front to the back. Does anyone know which lead on the back of a W212 Command Nav Box is the Aerial lead please.

Mud

I had an issue with the reception on my car and the dealer replaced that aerial amplifier that you pictured.

BlackJacks

Thanks for the response Mud,
I think I will try your suggestion and get one off ebay and see if it makes any difference.

I know cables can break and was just trying to circuit test to see if the Aerial Cable was good but I can't find it on the back of the head unit.
None of the cables look like what I would say was an aerial cable.

Mud

I hope that's the fix, in my case reception was dismal and many stations were "static-y". That unit was indeed somewhere there in the back . it was done under warranty so I really didn't fiddle with it. Service rep comment was that's the first item they usually check and replace for reception complaints.
I see where you mentioned your rear glass was replaced so I hope that installation was ok and did not impact the amplifier.

BlackJacks

Thanks for the reply Mud.
I found one on ebay this afternoon for £7.50 delivered (reduced from £22).
If it does not work I have not lost much as MB wanted £75 just to connect to their computer to find the problem then fixing it would be on top of that.

konigstiger

Carefully check rear window grid for damage. The antenna are an integral part of the wires in the rear window defroster. If fine, most common culprit is the antenna amplifier. Should be two, roof frame & c-pillar. If vehicle is equipped with keyless go and this feature it working fine, look to c-pillar amplifier first. Post or PM VIN I will pull part #s to comparison before disassembling.

Amplifier replacement see here: http://workshop-manuals.com/mercedes...ce_and_repair/ + next page
C-pillar: http://workshop-manuals.com/mercedes...m_at_c-pillar/ + next page
http://workshop-manuals.com/mercedes...ion/page_9943/ + next page

BlackJacks

Many thanks Konigstiger for a great reply.
I carefully circuit tested the printed circuits on the rear window back to the Red, Yellow and Green wire connectors and all showed a good circuit on all 3.
I will be taking the C-Pillar off tomorrow for a quick look. I have ordered an FM1 antenna amplifier that should be with me late next week from ebay.
I will post what I find out, fixed or not.

BlackJacks

A couple of photos of the FM2 Aerial Amplifier Near Side C Pillar

konigstiger

Image shows amplifier in/out connections IMHO speak with seller to have window replacement vendor revisit at no cost to you in effect confirming with MB that all connections are correct before replacing parts.

BlackJacks

Thanks for the photo. Mine has a cable support on the car and assuming MB don't fit things they don't have to . . . then a cable may be missing on my car! I did try to find a photo on Google but couldn't. Thanks for finding one. You are a star.

BlackJacks

My second hand FM1 (from eBay) arrived today. Fitted it in 10 minutes and the radio now works again.
Thanks for your help Mud.

BlackJacks

Thanks to everyone for their help

Mud

That's great, plus not a high cost !
Thanks for posting pics and outcome.

Arrie

This was a great thread!!!

Wonder how easy it is to fix poor AM radio reception??? Might be my area but comparing to my other car the E550 sucks on this.

konigstiger

FWIW MB released a bulletin on this, see attachment.

BlackJacks

I will do both FM1 and FM2, tomorrow, just to be on the safe side.
From memory, both Antenna Amplifiers make contact with the roof of the car via the thread on the bolt. I did think this would be enough but I will try this as it can't hurt.
I will remove and clean both contact areas and see what, if any, difference it makes and report back here.
Thanks for the update.

Arrie

Thanks stiger, I will look into this.

BlackJacks

Ok, I removed the FM1 Antenna Amplifier and sanded the raised (Sticking out, down) part of the bolt pillar that is part of the roof (rear right hand side). I replaced the FM1 and the reception got worse. Removed it and cleaned the contact area with an old (Clean and dry) toothbrush and replaced it. The FM reception then got better again. It might even have been better than before sanding. So logic dictates bad reception might have something to do with this connection. Along that line I ordered some "MG Carbon conductive grease 73ml" from RS Components (Radio Shack) for £17.94. Removed the FM1, light re-sand, and added a small amount of the conductive grease to the top (sanded part) of the pillar and the under side of the bolt head and thread. Replaced and checked. Not much difference to the FM reception but MW (Medium Wave) works very well. Caution this grease can get everywhere. If anyone tries this expensive "Black" grease, wear disposable gloves (on Both Hands), I only wore a glove on my right hand and still got grease on my left hand. I might need to do some research on FM, its reception and how Mercedes connects to it.