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@Benzrider17
I'm gonna give this a go. Amazon doesn't have the fiber optic decoder in stock at the moment, I'll have to check locally again. Between the local supplier and Amazon, there is about a $33 difference although he also doesn't have stock of the fiber optic decoder either.
Yeah, we are also missing quite a bit of options here, the wagon isn't at all popular here so there aren't many, don't know if we have the C55 wagon here at all. I work at the plant where my car was built and was there at the time, although I could never have afforded it back then. We have the original prototype in our museum, it's called the Black Mamba.
wow that’s kool take some pics would like to see it and yeah man go for it you could also try eBay but just make sure you ask seller for the correct decoder box for the fiber optic
wow that’s kool take some pics would like to see it and yeah man go for it you could also try eBay but just make sure you ask seller for the correct decoder box for the fiber optic
@Benzrider17
Just got my unit and fibre optic decoder yesterday, spent the whole day connecting it today. Have been battling since this afternoon with the unit, it comes on but has no sound. My fibre optic connector from the original harness is connected directly to the decoder and the RCA style connectors are connected directly to the rear output on the unit (LH and RH) with power, ground, and ACC tapped into the harness from the android unit. Tested these with a multi Meyer and there is power and continuity. Not sure where to go from here coz it just seems to not work no matter what I try. I plugged the original unit in to make sure that I hadn't damaged the fibre optic loop and it works. Don't know what more to try.
Also, where did you place the GPS unit? Looked everywhere for a place but the cavities ar just not that accessible.
AFAIK, the W203 doesn't have a 12v+ switched (ACC) wire in the stock radio harness. I think the stock radio is turned on by the canbus system. Is your ACC wire from the android unit wired to an actual ACC 12v+ switched source or did you just connect the android radio to the stock wiring harness? If the android unit is adapted to turn on by the canbus system just like the stock radio, you aren't getting an ACC signal to your decoder. I think the decoder requires an actual 12v switched source and won't turn on through the canbus system. You may have to grab a 12v switched signal from the cigarette lighter to turn your decoder on.
Did you wire the ACC wire from your Android unit to an actual 12v switched source? You stated you tested power, ground, and ACC with a multimeter, but to be clear, with the ignition off you get no volts through the "ACC" wire you tested, and with ignition on you do? To test if the decoder is defective you could temporarily jump your 12v constant to 12v switched to see if it turns on and you get sound from the amplifier.
Would be interested in your feedback on how it sounds if you get it working. I'd love to be wrong about my preconceived notions about the sound quality out of these android units.
AFAIK, the W203 doesn't have a 12v+ switched (ACC) wire in the stock radio harness. I think the stock radio is turned on by the canbus system. Is your ACC wire from the android unit wired to an actual ACC 12v+ switched source or did you just connect the android radio to the stock wiring harness? If the android unit is adapted to turn on by the canbus system just like the stock radio, you aren't getting an ACC signal to your decoder. I think the decoder requires an actual 12v switched source and won't turn on through the canbus system. You may have to grab a 12v switched signal from the cigarette lighter to turn your decoder on.
Did you wire the ACC wire from your Android unit to an actual 12v switched source? You stated you tested power, ground, and ACC with a multimeter, but to be clear, with the ignition off you get no volts through the "ACC" wire you tested, and with ignition on you do? To test if the decoder is defective you could temporarily jump your 12v constant to 12v switched to see if it turns on and you get sound from the amplifier.
Would be interested in your feedback on how it sounds if you get it working. I'd love to be wrong about my preconceived notions about the sound quality out of these android units.
@brauhaus313
Yes, I did originally jump the ACC from the constant 12v as shown in the below video (not so clear but it seems the guy joins them)
https://m.youtube.com/watch?v=RGDed1gton4 But I have it connected to the ACC from the Android harness now, you are correct, I didn't test this for switched power once I connected it, maybe all my testing yesterday was for nothing 😪
I also found another video that says that the amp power is from Canbus, gonna try this morning to see if I can set Canbus type on the radio, hopefully this will help. I'll post back with more info once tested.
Also, I went to a couple of sound install shops yesterday for help, seems nobody knowa about these setups, one shop offered to rewire my car for about $133. What a bunch of clowns.
If you jumped the 12v switched from the decoder to 12v constant it should have worked. I would suspect a bad decoder.
The amp is powered via the canbus as well. There is no remote amp turn on input on the Harman amp. I would at least try to wire the decoder up correctly with a switched 12v signal from the cigarette lighter and see if it works. If the decoder is bad, at least you will have the correct wiring ready to go once a replacement decoder comes in.
If you jumped the 12v switched from the decoder to 12v constant it should have worked. I would suspect a bad decoder.
The amp is powered via the canbus as well. There is no remote amp turn on input on the Harman amp. I would at least try to wire the decoder up correctly with a switched 12v signal from the cigarette lighter and see if it works. If the decoder is bad, at least you will have the correct wiring ready to go once a replacement decoder comes in.
@brauhaus313
Tested the connections again this morning, it seems that even the ACC from the Android harness is constant 12v but the unit has power. Also tried changing the Canbus settings on the radio, no dice.
Lastly, I've plugged the stock head unit in and noticed, with the fibre optics disconnected, it glows red from the outlet, should this not be the case with the decoder as well? When that system is connected, I see 'glow' from the fibre output, not sure if this is maybe a clue?
AFAIK, the signal used to carry audio information in fiberoptic cables is in infrared frequencies (invisible). The red glow is simply used to trace signals and locate faults. So, it could be that the decoder would glow red if it were properly functioning and turned on. However, I wouldn't say that definitively, because the manufacturers may have just omitted the red light. I mean, we are talking made in China parts here.
I think the bottom line is if the decoder is not turning on even when the ACC is connected to 12v constant, it's probably bad. You can't return it for exchange? These decoders seem to have a fairly high failure/non-functioning rate going by reviews online.
@brauhaus313
Tested the connections again this morning, it seems that even the ACC from the Android harness is constant 12v but the unit has power. Also tried changing the Canbus settings on the radio, no dice.
Lastly, I've plugged the stock head unit in and noticed, with the fibre optics disconnected, it glows red from the outlet, should this not be the case with the decoder as well? When that system is connected, I see 'glow' from the fibre output, not sure if this is maybe a clue?
I would look into why the ACC from the headunit is 12v constant even with the ignition off. If the ACC wire from the headunit is for some reason constant when it should be switched, hardwiring the decoder to a constant 12v will drain your battery. Are you sure you wired everything up correctly?
I would look into why the ACC from the headunit is 12v constant even with the ignition off. If the ACC wire from the headunit is for some reason constant when it should be switched, hardwiring the decoder to a constant 12v will drain your battery. Are you sure you wired everything up correctly?
Yes, everything is wired correctly as far as I can tell. The android unit plugs into the factory harness, radio has power and seems to be working in every way besides sound. Fibre optic cable also plugged into decoder and decoder is wired into the Android harness loom, has power but the ACC might be an issue (can check it out if it works). The aux L/R in on the decoder is connected to the L/R out on the radio (tried front and rear). Decoder box doesn't show red glow for fibre as the factory unit does when plugged in. I guess the decoder is faulty, it the head unit. Is there any way to tell whether the head unit is outputting sound? Or to input another audio source into the decoder to check if there is sound?
To check if your radio RCA's are putting out a signal you can check voltage (outer jacket and inner sleeve, or connect rca cable and check voltage on outer jacket and inner pin with music playing) or you can connect rca cables from the headunit to another audio receiver like a home audio receiver if you have one handy. Just have to temporarily set up the home audio receiver nearby the car.
For the decoder you could run a signal from the 1/8" jack from your phone via a 1/8" jack to rca splitter, or rca's from a home audio receiver into the decoder to see if it is receiving a signal.
If you trace the ACC wire from the headunit to the car's wiring harness, what wire is the ACC wire from the headunit wired to? A few pictures could really help. If your car's radio harness does not have an ACC wire in it, the headunit's ACC wire should not have any voltage at all. A radio's ACC wire accepts a switched 12v input. That same switched 12v input would turn on your decoder. As indicated on the thread I linked to (and here https://mbworld.org/forums/c-class-w...ml#post5550729) W203's don't have a switched 12v in the radio harness, thus you have to grab a switched 12v from elsewhere, like the cigarette lighter. That you have a constant 12v on the ACC wire from your headunit strongly suggests something in the wiring isn't right.
Does the back of your headunit look like the following?
I'm getting a little confused by your phrasing ie. "I guess the decoder is faulty, it the head unit."
Have you tried wiring the decoder to a proper switched 12v source like the cigarette lighter yet?
Last edited by brauhaus313; 10-24-2021 at 04:49 PM.
I used power from cigarette lighter red yellow to power black ground for decoder box and yes the red light n decoder box flashes on mine just one
check all connects and make sure decoder box is the correct t one (Porsche Mercedes )
Are you getting sound out of all your speakers including subwoofer with this decoder? You aren't able to actually fade front/rear even if you adjust fade on your headunit, correct?
Are you getting sound out of all your speakers including subwoofer with this decoder? You aren't able to actually fade front/rear even if you adjust fade on your headunit, correct?
I have a option bass button and seems to be working fine with fade and dash base speaker also back base that comes in the side compartment where the factory amp is
I had purchased my first decoder box which was not working so I returned it and purchased this one that was recommended by friend it been working fine
To check if your radio RCA's are putting out a signal you can check voltage (outer jacket and inner sleeve, or connect rca cable and check voltage on outer jacket and inner pin with music playing) or you can connect rca cables from the headunit to another audio receiver like a home audio receiver if you have one handy. Just have to temporarily set up the home audio receiver nearby the car.
For the decoder you could run a signal from the 1/8" jack from your phone via a 1/8" jack to rca splitter, or rca's from a home audio receiver into the decoder to see if it is receiving a signal.
If you trace the ACC wire from the headunit to the car's wiring harness, what wire is the ACC wire from the headunit wired to? A few pictures could really help. If your car's radio harness does not have an ACC wire in it, the headunit's ACC wire should not have any voltage at all. A radio's ACC wire accepts a switched 12v input. That same switched 12v input would turn on your decoder. As indicated on the thread I linked to (and here https://mbworld.org/forums/c-class-w...ml#post5550729) W203's don't have a switched 12v in the radio harness, thus you have to grab a switched 12v from elsewhere, like the cigarette lighter. That you have a constant 12v on the ACC wire from your headunit strongly suggests something in the wiring isn't right.
Does the back of your headunit look like the following?
I'm getting a little confused by your phrasing ie. "I guess the decoder is faulty, it the head unit."
Have you tried wiring the decoder to a proper switched 12v source like the cigarette lighter yet?
@brauhaus313
Sorry, I typed on my phone and it probably auto-corrected. I meant that it's either the head unit or the decoder that is faulty.
I did try headphone to RCA input into the decoder, nothing. I didn't try head unit output into another source, I have a radio in my garage that could serve that purpose which I'll try tomorrow if I have the time.
For me, at least in testing, it shouldn't matter that the ACC is constant, this can always be fixed later but perhaps this is the issue? I did try ground and constant 12v from the lighter yesterday, didn't help although I will try with ACC again tomorrow.
My head unit has pretty much the same outputs as the picture - I haven't done any significant changes besides tapping the decoder inputs into the head unit harness. The outputs are on a harness with a bunch of female RCA style connectors though and not directly on the radio. I'll have to have a look at the diagram a bit closer to check the connections but, at first glance, it seems that it is matching to what I've done.
Lastly, I really appreciate all your help and patience, especially you're taking time to post the detailed responses. I will post some pictures tomorrow if I get to it and hopefully this can be sorted.
I used power from cigarette lighter red yellow to power black ground for decoder box and yes the red light n decoder box flashes on mine just one
check all connects and make sure decoder box is the correct t one (Porsche Mercedes )
@Benzrider17
The decoder I have is the one ordered with the unit, it has no red glow coming from it. I can post a picture of it if I get to the car tomorrow, it's blue but the connections are exactly the same.
For me, at least in testing, it shouldn't matter that the ACC is constant, this can always be fixed later but perhaps this is the issue? I did try ground and constant 12v from the lighter yesterday, didn't help although I will try with ACC again tomorrow.
I agree, and as I've stated, the decoder should turn on if the switched wire is jumped to 12v constant. In terms of something not being "right" I was only referring to the acc wire shouldn't be hot all the time, not that it would be the cause of the decoder not functioning. Hope you get it sorted and again, would appreciate if you come back with your impressions on how it works/sounds.
I agree, and as I've stated, the decoder should turn on if the switched wire is jumped to 12v constant. In terms of something not being "right" I was only referring to the acc wire shouldn't be hot all the time, not that it would be the cause of the decoder not functioning. Hope you get it sorted and again, would appreciate if you come back with your impressions on how it works/sounds.
@brauhaus313
This evening, I tried what you suggested - taking line out from the head unit to an independent source, the front had sound but strangely enough, not the rear outputs. I then tried to connect line out to the decoder, totally dead, not even a glow on the fibre output. I also connected the decoder to the cigarette lighter as suggested, just to get the switched 12v. Here are some pictures of the unit and installation, where the red splice connectors are is where I've taken the decoder into the Android unit harness. Face of Android Rear of unit Canbus unit, steering controls work Front out connectors to decoder Decoder connected ACC wire from Android unit (always live) to decoder Constant and negative splice in on Android harness
It does seem the decoder is defective doesn't it? Why you aren't getting a signal out of the rear outputs is strange as well. I think you've done enough trouble shooting and it's time for an exchange or refund. Maybe the replacement headunit/decoder will work properly. I would have gone with your original plan of the Kenwood headunit. Good luck.
It does seem the decoder is defective doesn't it? Why you aren't getting a signal out of the rear outputs is strange as well. I think you've done enough trouble shooting and it's time for an exchange or refund. Maybe the replacement headunit/decoder will work properly. I would have gone with your original plan of the Kenwood headunit. Good luck.
@brauhaus313
Yes, that was the best option although, the decoder and Canbus unit on its own, was more than 50% of what I paid for this setup. But then again, it would've worked with no hassles and probably more reliable, so there's the trade-off. I did a video call with the seller to check the install, all is correctly wired. He confirmed that the decoder is probably dead, said he had the same issue with an ML install from the same batch of decoders today. Also said that there should be a red glow from one of the fibre optic ports on the decoder. He has ordered new stock of decoders from a different manufacturer, these will only be in middle of November. I'll post back here and let you know about the sound, if all is working. Thanks for all the help, I highly appreciate it!
@Benzrider17
Just got a replacement decoder today, same story. I wonder if the decoder is not correct or whether there is another issue. Can you tell me whether you have the factory CD changer and whether this is disconnected? Maybe, the new radio cannot activate the CD changer and the fiber optic loop is broken? I came across this post, it's D2b but perhaps this could be the same issue. It would be useful to know what to do with the CD changer. https://www.benzworld.org/threads/a-...works.3079534/
Hey sly1980 sorry you having all these issues if you have the exact decoder I send you in this post it has to work as you connect the rca jacks give them a twist
the ones going to the decoder box red light should be flashing and yes I have a cd changer in the glove box there’s a connection behind it as well but didn’t have to alter anything ,but you could check the loop Connecting it one screw on the right side top with release the cd changer it pulls up towards the left after unscrewing that one screw
red and yellow to power and black to ground same connection I made to cigarette lighter
Hey sly1980 sorry you having all these issues if you have the exact decoder I send you in this post it has to work as you connect the rca jacks give them a twist
the ones going to the decoder box red light should be flashing and yes I have a cd changer in the glove box there’s a connection behind it as well but didn’t have to alter anything ,but you could check the loop Connecting it one screw on the right side top with release the cd changer it pulls up towards the left after unscrewing that one screw
red and yellow to power and black to ground same connection I made to cigarette lighter
@Benzrider
The unit is not the same as the one you recommended as I couldn't find that on Amazon. The replacement unit came from the company I ordered the new Radio from, they had agreed to replace the decoder but it took about three weeks to come. I ordered another decoder from Amazon this time, hopefully it will arrive soon. Shipping is always an issue to South Africa, our customs presents the biggest holdup. I ordered this decoder, says it's W203 compatible.
Yeah customs agents been going in on checking packages I just ordered some steering wheels and waiting 2 months to arrive but finally here
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
10-11-2021, 11:19 PM
