pharris857

2006 CLK500 convertible. 2 issues key fob no longer works and radio has weak reception. New batteries in key fob. Fuse #8 blown in trunk. Replaced and it blew immediately. In reading some of the forums on the key fob issues it would appear these are related. Anyone know where the antenna amplifier is on this car. Any help would be appreciated!

Glyn M Ruck

You will find both Coupe & Cab data here thanks to me being dumb.

https://mbworld.org/forums/clk-class...enna+amplifier

benzybenz

Registered to say I'm having the exact same problem.

My buddy was messing around and set off my alarm using the panic button - key stopped working after that unless it's pointed directly at the driver side door (found that solution in another post on here). Appears to be an issue with the RF receiver??

Glyn M Ruck

Can be metallic tint, damaged wire into rear screen antenna, damaged rear screen, bad connection at sticky pad, bad earth or blown RF antenna amplifier. Damaged key or flat battery in key.

benzybenz

Glyn, thanks for the reply.

The tint is the same that's been on the car since I've owned it (4 years), so I'm assuming it's not interference from that. And we can also rule out cutting of wires during an installation.

The key itself will work to unlock/lock the car at extremely close range on the driver's side. I've replaced the battery in the key. I have also tried my spare key and it is responding the same way, so I don't think it's a key issue.

Like pharris, my #8 fuse is blown and pops every time I try to install a new fuse, so I must have a short somewhere. Is it possible to damage the rear screen/wiring/antenna amplifier just by setting off the alarm? Is there a way for me to test where the short is coming from (I don't have any special equipment or tools, just an individual MB owner)?

Rudeney

Fuse #8 also feed the Anti-Theft Alarm horn. Is suspect that it has died. using the panic button didn't in and of itself kill it, but it probably "revealed" the failure. The ATA unit is in the fender, behind the passenger front wheel. You'll have to remove the plastic shroud to get to it. For now, just unplug it to see if this stops blowing the fuse. If so, you;ll need to either do without the alarm or replace it. They tend to "deteriorate" from road salt and other environmental exposure.

Glyn M Ruck

+1^

benzybenz

Do you guys think it's more likely to be the ATA horn unit(item #20), or the Alarm Control Unit (item #100 in the pic below)?

Rudeney, when you say I have to remove the plastic shroud, are you referring to the plastic cover in the wheel well?

Rudeney

It's probably the horn. It has a "backup" battery in it that can die and it may be what is causing the short. Yes, the the wheel well shroud need to be removed. You'll probably want to jack the car and remove the wheel to make this easier.

benzybenz

Great, thank you very much!

I'll try to give that a shot this weekend and let you know how it goes.

Cheers!

benzybenz

Hey guys,

Just checking back in to report that your suggested fix worked like a charm. I disconnected the ATA horn in the front passenger wheel well and inserted a new fuse into the #8 slot. Fuse didn't blow and my key works from a distance now. Radio is sounding much better, and I can use the built-in garage door opener again.

The plastic shroud was a bit of a pain to maneuver in and out. All in all it was about a 1 - 1.5 hour job.

Thanks again!

Rudeney

Glad yo got it sorted out. If you want to replace the ATA horn, it's about $150 (assuming you are in the USA):

http://www.parts.com/parts/2008/Merc...component=HORN

dbbrawner

2007 clk350.
Key fob unlocks, locks and opens the trunk only when held up to the sensor. New batteries. New fob. Number 8 fuse okay. Radio has good reception.

Rudeney

That sounds like a failed antenna amp. It's not as common on the W209, but rampant on the W203.

cturner

Can you tell me what you did to fix this. Local dealer suggested $4800. ECM There must be less involved thsn 5k plus ti mmake key remote work and get a couple of stations.

Konstantin79

Thank you very much for advice!!! Had the same issue on my CDI270. Whe got the access to the horn, found the connector is full of water and of course 7.5A fuse was blown. Cleaned and dried the connector, reconnected, installed new fuse and all works fine). Also i sealed the connector to prevent moisture intrusion in the future

05CLKCabriolet

Just want to say thanks, I picked up a 6,000 mile 2005 CLK 320 cabriolet this past spring to be used for my wife's summer car and a few weeks ago the FM signal became non-existant and the key fob only worked right at the door handle, did some googling and I found this thread and all is good now!