C55 Harmon Kardon Radio upgrade
that decoder should be good I had a few little issues connecting it myself in the beginning but once I had the right decoder box it was simple plug and play
they should just have it built in already like the steering wheel control box but hopefully this one will arrive soon and you should be listening to some kool tunes
My decoder arrived today, quite impressed with the delivery time from Amazon, just on one week.
Connected everything and finally, there is sound! Problem is, the sound is really soft, not sure why this is, basically on radio startup, half volume is inaudible, at max volume is just softer than normal listening volume. I don't know, it seems like this car is intent on messing me around. I'm officially out of solutions at this point, plugging the original radio in produces proper sound.
"Update"
I instead connected a phone to the decoder and sound is normal seems like the output from the radio is weak. Not sure if there is a setting on the radio to fix this but I've already checked the equaliser.
Last edited by Sly1980; Nov 25, 2021 at 01:15 PM.
My decoder arrived today, quite impressed with the delivery time from Amazon, just on one week.
Connected everything and finally, there is sound! Problem is, the sound is really soft, not sure why this is, basically on radio startup, half volume is inaudible, at max volume is just softer than normal listening volume. I don't know, it seems like this car is intent on messing me around. I'm officially out of solutions at this point, plugging the original radio in produces proper sound.
"Update"
I instead connected a phone to the decoder and sound is normal seems like the output from the radio is weak. Not sure if there is a setting on the radio to fix this but I've already checked the equaliser.
one word of advice don’t mess with the master setting or factory setting 0000 if you want to access it but be careful not to change any if your not sure what it’s for
there’s lots of drop down options on that screen .
one word of advice don’t mess with the master setting or factory setting 0000 if you want to access it but be careful not to change any if your not sure what it’s for
there’s lots of drop down options on that screen .
Thank you for the response.
I fear that the radio output is too weak, spoke to the supplier today and they said that I should increase the gain and when checked, it is already at max. Loud is also on and when I start that V8 with the door open, you cannot hear the radio, even though it's at max volume. I also then disconnected the RCA out between the radio and decoder and instead connected my iPhone to the decoder, sound is brilliant! So, I guess the radio is faulty, I don't think that there are any settings that would bring the sound level up.
Finally got my radio installed today, after months of struggling. I have to get a 9" unit as the 7" unit was out of stock from the local supplier (South Africa sucks in this regard!) Anyway, the sound is great, a bit better than the stock unit. The best quality I got out of the head unit was when using CD's but it sounds better now with Bluetooth. We'll have to see what long term usage reveals about the head unit.
Anyway, the last question is, how do I set the time in the instrument cluster now that I have the android unit? I checked the settings menu but there is no time & date option there 🤷
Thanks for the response! The option just isn't there, it gets time from the Comand unit, plugged it back in and it got the time from GPS. Apparently, the cluster has to be reprogrammed to not look for the Command unit and GPS time, so I need a star diagnostics tool to get that done. This will be ok until the battery gets disconnected. Lastly, the unit actually sounds much better than the stock head unit once I played with the DSP settings. Here is a pic of the install:
Not really crazy about the non-stock look but hey, the unit is much higher spec.
Anyway, thanks for all the help and advice, it is really appreciated. Hope you have a wonderful festive season!
i like the screen size but I also like the Oem look . I’m using the USB ports for my music option think it sounds better on my unit
specially videos sound even better with very good picture quality
My main question is for best practice, I should connect the MOST fiber converter box to ACC so I avoid a parasitic drain on my battery right? I saw some people hooking it straight into main 12v but I would imagine the box then stays on all the time and slowly drains the battery.
The Best of Mercedes & AMG
On the MOST sound converter, are you sure you hooked the ACC wire to a proper source? I hooked it up to the cigarete lighter. If you connect the ACC to a constant source, the sound WONT WORK. The harness on the C55 doesn't have ACC source, its all on all the time. The MOST box needs that signal when you flip over our car key switch to tell the sound amp to turn on, otherwise no sound.
The main thing with the canbus is that if will tell the radio to turn on when you turn the key, in that case the signal comes thru canbus (or at least it does for mine, I didn't have to hook the ACC to the radio).
On the MOST sound converter, are you sure you hooked the ACC wire to a proper source? I hooked it up to the cigarete lighter. If you connect the ACC to a constant source, the sound WONT WORK. The harness on the C55 doesn't have ACC source, its all on all the time. The MOST box needs that signal when you flip over our car key switch to tell the sound amp to turn on, otherwise no sound.
The main thing with the canbus is that if will tell the radio to turn on when you turn the key, in that case the signal comes thru canbus (or at least it does for mine, I didn't have to hook the ACC to the radio).
Thanks for the input. eBay Junsun radio seller provided the instructions to wire to the canbus. I can only think it is to signal the amp to turn on.
I am trying to figure out how to setup the volume buttons on the steering wheel. The instructions in the radio manual did not work...
Thanks for the response! The option just isn't there, it gets time from the Comand unit, plugged it back in and it got the time from GPS. Apparently, the cluster has to be reprogrammed to not look for the Command unit and GPS time, so I need a star diagnostics tool to get that done. This will be ok until the battery gets disconnected. Lastly, the unit actually sounds much better than the stock head unit once I played with the DSP settings. Here is a pic of the install:
Not really crazy about the non-stock look but hey, the unit is much higher spec.
Anyway, thanks for all the help and advice, it is really appreciated. Hope you have a wonderful festive season!
Last edited by Scoom; Oct 29, 2024 at 02:23 AM.







