xxZZxx

I recently got a new battery for my CLK55 and replaced it at Oreilly's. Since then there would be no sound coming from the speakers, even though Command is on and not muted. I can switch radio channels and between CD/radio/AUX, and I have tried plugging in my phone and CDs and there would still be no audio. I asked the guys at Oreilly's and they said the car might have a charging module that needs to be reset by MB? I only got the car recently so I am still getting familiar to it. Is this a known issue that I need to bring to the dealership?

I have also tried resetting everything by disconnecting the battery for 5+ min, but still same problem. Also since the replacement I can only adjust the headrest up but cannot power it down (not sure if relevant).

Thanks everybody!

My car: 2005 CLK55 AMG, the speakers are Harmon Kardon

400ixl

Got an amp and blown the fuse?

insame1

Was your key in the ignition when they swapped the battery? Have you had an issues with the system before that?

xxZZxx

I can't remember if the keys were in the ignition or not, and I did not have any issues with the system before changing the battery.

MarcusF

Leaving the keys in the ignition while changing the battery is a very bad idea. However, if the car starts, I don't think that's the problem.

Do COMAND units require a code after losing power? Other MB HUs do, and they won't produce any sound until the code is entered.

xxZZxx

Yea I know some cars have a radio code so I called the MB dealership and they did gave me a code for my VIN. The weird thing is there is never a prompt to enter any code on Command and even after I disconnected the battery for 5 min and reconnected it, Command would start up just like normal, minus the sound part.

insame1

I have pulled my battery many times and never lost command. I am guessing fuse. I have seen the key left in do some weird things like fry the headlight ballasts.

xxZZxx

I checked the fuse under the dash and it's still good. Is there another fuse box I should check?