What does the Antenna Booster actually do.

[John77]

I have tracked a fault to my Antenna Booster. What exactly does it do. Radio? Sat Nav? Phone? Door Locks? all or any of these? Do I really need it? Where is it situated. 2006 SLK 200.

 

[Blobcat]

It amplifies the low level signal received into a signal that the radio and locking system can use. Without it you'll have poor radio reception and you'll be unlikely to unlock the car from the buttons on the key.

 

[John77]

It amplifies the low level signal received into a signal that the radio and locking system can use. Without it you'll have poor radio reception and you'll be unlikely to unlock the car from the buttons on the key.

Thank you. I will have to try and find the fault.

Crackle from the Battery

I have problems with my wife's 2006 SLK 200 having a flat battery after a few days. Totally flat. Will not even open the doors. Anyway short story, done drain checks on fuses, but on fully charging the battery each time I have connected the battery and heard a noise that I thought was just the...

forums.mercedesclub.org.uk

 

[John77]

It amplifies the low level signal received into a signal that the radio and locking system can use. Without it you'll have poor radio reception and you'll be unlikely to unlock the car from the buttons on the key.

You are correct, no central locking, but great radio reception still. Where do you find this booster??

 

[Botus]

cars can have multiple antennas - most keyless cars have an individual one for each door and the boot, a DAB one, a TV, a Bluetooth, a FM etc. and then one for the ignition switch

did you replace the batteries in the key fobs?

 

[star]

Is the aerial top still on the n/s/r wing?

 

[John77]

Is the aerial top still on the n/s/r wing?

Hi thank you for the reply. Yes still in place. No matter how close I get to the car or aerial, the fob will not open the car. The fuse for the Antenna Booster has been removed because my battery was going flat after 2-3 days and on connecting the battery, the battery crackles, see that post to see how I came to this conclusion and now there is no crackle on connecting the battery (No I do not mean the sparking you get as the clamp is put on). If I put the fuse back in, the battery crackles again for up to 20 seconds. Not a hiss, a crackle. Remove the fuse and reconnect and it doesn't do it, so probably the booster at fault, but I have not got any further yet. This is why I asked what it did and probably why the locking now doesn't work now. I will investigate further when I have time and if I find out where the booster is.

 

[Chrishazle]

On a C class estate of that age the antenna booster is in the top of the tailgate behind the trim panel, maybe it's the same on the E class.

 

[sonic]

Hi thank you for the reply. Yes still in place. No matter how close I get to the car or aerial, the fob will not open the car. The fuse for the Antenna Booster has been removed because my battery was going flat after 2-3 days and on connecting the battery, the battery crackles, see that post to see how I came to this conclusion and now there is no crackle on connecting the battery (No I do not mean the sparking you get as the clamp is put on). If I put the fuse back in, the battery crackles again for up to 20 seconds. Not a hiss, a crackle. Remove the fuse and reconnect and it doesn't do it, so probably the booster at fault, but I have not got any further yet. This is why I asked what it did and probably why the locking now doesn't work now. I will investigate further when I have time and if I find out where the booster is.

I might be wrong but I don't think the antenna booster is used in the remote locking/unlocking of the car.
You seem to have a short or heavy power drain in that circuit, but that circuit should only work with the ignition on. So I suspect you have two separate faults, does the radio work?

 

[John77]

On a C class estate of that age the antenna booster is in the top of the tailgate behind the trim panel, maybe it's the same on the E class.

Thank you for the reply, but at the beginning it does say that the car is a 2006 SLK 200. Do you know where it is on yours?

 

[Chrishazle]

Apologies John, I missed that, thought it was your E200 you were talking about. I have no idea where it is on my SLK, but maybe @Blobcat can help as he has an SLK as his daily!

 

[Blobcat]

Apologies John, I missed that, thought it was your E200 you were talking about. I have no idea where it is on my SLK, but maybe @Blobcat can help as he has an SLK as his daily!

Mine works.. so I've not looked for it...

However - it should be in the boot on the side

 

[Kev555]

Just out of interest on my Vito ive always had a poor radio reception, does anybody know where the antenna amplifier is located on those?

 

[Mark A]

On my old 171 I had a few issues with poor reception and unlocking. I traced it back to a poor contact being made between the antenna and the screw in base. A good clean sorted it.

 

[John77]

I might be wrong but I don't think the antenna booster is used in the remote locking/unlocking of the car.
You seem to have a short or heavy power drain in that circuit, but that circuit should only work with the ignition on. So I suspect you have two separate faults, does the radio work?

Hi yes thank you for the reply. The radio works fine. I have ben told by one of the MB Specialists on here that it does boost the locking signal and if you do remove the aerial off an SLK for any reason, you cannot unlock the car unless you go next to the aerial. I will have to find the booster and take a look further. I am leaving the car unused for a few days to see if the battery still drains.

Mine works.. so I've not looked for it...

However - it should be in the boot on the side

View attachment 69893
View attachment 69894

Thank you for that I will take a look later. Just called in to Mercedes as I passed to see how much a new one was in case I needed one. Around £470. I will take this one off and check it lol.

 

[Chrishazle]

When you access the existing booster take the part number off it and Google search for it - many years ago I did this for my S203, the MB new price was about £100+, I got a brand new one off eBay for £25 - which I never used, and Alexander Foti (AMF Automotive) may still have!

 

[John77]

When you access the existing booster take the part number off it and Google search for it - many years ago I did this for my S203, the MB new price was about £100+, I got a brand new one off eBay for £25 - which I never used, and Alexander Foti (AMF Automotive) may still have!

Thank you I will get it off and take a look.

 

[John77]

Well found it thanks to Blobcat. The next thing is how do I remove the Antenna Plug, see photo. I have tried pulling , but I think that it must have a lock of some kind on the black plastic collar and I definitely do not want to break it. Also the Exide Excell car battery has a little window and shows the state of the battery and when fully charged it is green. Well 24 hours have passed with the battery connected and it is still fully charged. I will see how it is in a few days, which before disconnecting the fuse for the Antenna Booster would have been totally flat, no charge at all. Well if it stay charged, the the only conclusion is that this is the problem.
I now want to remove each lead at a time from the booster with the battery disconnected and the put the fuse back and reconnect the battery to see if it still crackles with that lead removed, so that I can rule out it just being the Antenna or Radio connections. If it still crackles with the 2 leads removed, it must be a fault somewhere on the Booster. Of course as a last test remove the power leads to the Booster and if it then does not crackle it is the booster, but if it still does, it is the wiring, not the booster. Only time will tell.

 

[Blobcat]

Well found it thanks to Blobcat. The next thing is how do I remove the Antenna Plug, see photo. I have tried pulling , but I think that it must have a lock of some kind on the black plastic collar and I definitely do not want to break it. Also the Exide Excell car battery has a little window and shows the state of the battery and when fully charged it is green. Well 24 hours have passed with the battery connected and it is still fully charged. I will see how it is in a few days, which before disconnecting the fuse for the Antenna Booster would have been totally flat, no charge at all. Well if it stay charged, the the only conclusion is that this is the problem.
I now want to remove each lead at a time from the booster with the battery disconnected and the put the fuse back and reconnect the battery to see if it still crackles with that lead removed, so that I can rule out it just being the Antenna or Radio connections. If it still crackles with the 2 leads removed, it must be a fault somewhere on the Booster. Of course as a last test remove the power leads to the Booster and if it then does not crackle it is the booster, but if it still does, it is the wiring, not the booster. Only time will tell.

There appears to be a collar on the connector on the amp so the black collar may turn to release it.

 

[Chrishazle]

Quite a few pre-owned ones on eBay somewhat cheaper than MB! search mercedes slk r171 antenna amplifier.