Good Day Friends - I have a 2023 XTRONS 9" Android 12 4+64 HU. I am having trouble connecting/receiving power to the HU and would like a Straight Forward guide and help to successfully install DIY. I searched all over YouTube and the web, without success, there are so many videos and I tried to piece them together and made an attempt. I have a 2004 E55 W211 USA, and have connected the B+ and the Ground of the XTRONS Fiber Optics Decoder box to the Cigarette Lighter power and ground wires. I have also joined the red ACC wire from the Xtrons wire harness to the positive wire of the cigarette lighter to power of/off with the ignition only. The CD Changer is left in place with its original Fiber Optics connected. I've used the Green and Green/Black CANBUS wires separately provided by XTRONS, joined them to the Green and Green/Black XTRONS harness and connected those to the Canbus switch underneath the Glove Box compartment in the 7th Slot. I Verified that power is going to the cigarette lighter at 12.5 DC volts, yet the HU is not powering up. My CD Changer will not open, however the Hazard lights are working and all the other functions on that part. Appreciate all the help the forum can provide.

 

B+ wire(s) should be connected to a constant 12v source, not a switched source. That should not keep it from booting up however. After fighting my Android HU for a while, I find it best to bench test to make sure everything works before installing it in the car. If you have a 12v supply that outputs at least 1.5 amps I would recommend doing that first to iron out problems.

As an aside, the CD changer door will no longer open once you remove the stock HU. You can install a module to allow for it to work again if you want to access the space after removing the CD changer. I wrote up my experience here: https://mbworld.org/forums/w211-amg/...ad-unit-2.html
Scroll to the bottom for the details on the module.

 

Hi MJBelcher500, thanks for the prompt response. I only have (1) B+ wire that comes from the XTRONS decoder box and (1) ground wire. It was recommended in multiple posts to connect those to the Cigarette lighter to only be intended to power when the ignition is turned, and avoid the constant power method and possible battery drain. I do not have a portable 12v to test, I will have to purchase one tomorrow.

Unfortunately the new HU is one piece that blocks the CD changer from opening, however, thank you for letting me know that it could only open when the original HU is connected.

I'm just trying to find someone that can show pictures of a late model XTRONS unit wired to a W211, most threads are 5 years old and only somewhat helpful. when I get my hands on a 12v supply, I'll let you know if the unit is defected. **I did notice that the Xtrons decoder was receiving power because I seen green lights in the little box....

 

I do not have an XTRONS. Do they use a separate Fiber Optic convertor or is it built into the HU? If it is separate, do you have a +12 line going to the HU itself? Normally, it would need its own +12 and ground. The convertor needs a switched 12v. The HU generally uses both a switched 12v and a constant 12V source. DO you have any install guide from XTRONS you could post?

Something like this:

 

While I haven’t had time to do my E I did my Gwagon year ago and found that Xtrons has 2 diff CAN decoders for the power. The diff is 1 extra wire if I recall. I don’t know which ended up working for me but that 1 wire makes the diff between working or not.

here are the Amazon links to them.
XTRONS® Optical Fiber Head Unit Replacement Decoder Box for Mercedes-Benz E/CLS/SLK/SL/CLK Series https://a.co/d/dLirC0f

XTRONS® Optical Fiber Head Unit Replacement Decoder for Mercedes-Benz CL/CLS/E/S/SL/SLK https://a.co/d/5dAtPq7

 

That is very interesting, I have the decoder box that only has the B+ yellow and Ground black wire. “The first link”. In your second link, i see the only difference is that extra 3rd wire which is the additional ACC red wire. In my case there is a ACC red wire coming out of the Xtrons wire harness and I used that to connect to the cig lighter. So question is, do you recall using Both the ACC from the Xtrons harness and the ACC from the Xtrons Decoder and connected to the cig lighter?

Thanks for pointing out that second model.

 

You to confirm, you are saying the HU is not powering up correct? The fiber optic box does not need to even be in the loop for the HU to boot up. Are you only having issues with the fiber optic box or the HU?

 

**Only having issues Powering Up the HU. Has not powered up at all.

 

Ok, that has nothing to do with the fiber optic box. Does the XTRONS come with a plug in harness or do you need to splice into the car's wiring? I would pull the unit out and work on getting it powered up before doing anything else.

 

I ordered a Mercedes CANBUS radio adapter harness on aliexpress to connect my Android Head Unit. only problem is it isn't passing through all the CAN steering wheel signals, but power, automatic dimming with headlights and such work fine.

Similar to this. Power on signal comes from the factory amp or canbus in the trunk which this wiring passes forward to the head unit up front. I'll soon be installing my Helix DSP to map out to all 7 audio channels versus current usage of 4.

https://www.aliexpress.us/item/32568...d=qNuoQTDsllIE

actually, just ordered this same exact one in hopes it'll pass through my steering wheel controls versus my existing canbus box and harness.

 

Current Wiring - I may have to bring in the power from the factory amp? I di fail to mention that my stock radio. Is the 12- Speaker Logic Harman/ Kardon

 

It's difficult to see all of the markings on the wires to the unit in the pics you posted. You need to focus on the basics. You do not need the CAN module or the Fiber Optic box in the loop just to boot up the main HU. You need to find the main ground wire and power wire(s) that go to the HU. There are most likely two power wires. One constant 12v the other switched 12v. Wire in a 12V source to those and then connect the ground wire to a known good ground. If you cannot get the unit to boot up, you are wasting effort with the rest of the system.

 

There isn't a plug thing for the CAN connector to plug into with the new HU? If I recall on my Gwagon it was connected to a plug and then somehow to the new HU. I could be slightly wrong but I know 100% the CAN plug was connected someplace. I can swing by storage in the next day or so and look at the wiring from the HU since I drowned my G last year and never replaced it.

 

the modern android head units pass through CAN through the illuminate and parking wires from the CAN box. i believe its those two wires.

but as shown it look like this is possibly going through the teal, and teal/white wire?

 

I may have power issues with the cig lighter, because when the ignition is on, it is not receiving any voltage.

*** I found another Vid where there is another Harness either purchased separately or shipped with another model that connects back to the AMPlifer in the Trunk/boot in order to provide power to the HU.

 

Please, just find a 12v source that works and connect it directly to the HU. Don't order any more parts or harnesses until you can verify that the HU even functions. It should only take a couple of minutes to temporarily wire power directly to the HU. Once you see it boot up (if it does) then further wiring changes can be made if necessary.

 

I am installing an (used) XTRONS in my E55. I have the unit powered up, and the MOST connected with the adapter box. My XTRONS also came with a CAN bus decoder. However, as received, the green wires for CAN seem to be connected to the MOST box. Question is, what breaks out to the car's CAN-B bus? Is everyone grabbing a connection at the distribution block in the upper left of the right foot well? Does the MOST box even need to be connected to CAN?

As of now, the radio powers up, but no audio out in the car.

Second set of questions: What is everyone doing for the antenna connections? The XTRONS comes with its own GPS antenna, but I am thinking about running two Fakra extension cables to the trunk, and picking up the stock antenna connectors back there (one for radio, one for GPS). Has anyone done something similar to this? I'd like to avoid an extra GPS puck sitting on the dash.

 

I used an adapter to connect to the OEM radio antenna. I tried using the OEM GPS antenna, but it did not work. I ended up using the antenna provided in my kit and mounting it above the instrument cluster (you need to pop out the surround to do this).

The Fiber Optic box does not need to be connected to the CAN module. It may just be a +12v connection you are seeing. The CAN module does need power and ground, I connected the two CAN leads to the distribution block in the passenger footwell area.

If the Fiber Optic box is connected correctly you should have sound. Make sure it is powered up and that the correct RCA connectors are plugged in.

 

Fiber Optic box is hooked up. What did you do with the two green wires from that box? Part of my problem is that this is a used setup, and it came in a pile with some things connected, some things not. The Fiber Optic box was connected to the CAN decoder harness, as there is a matching connector on those green wires. I will try to get a picture of it all. I have not hooked into the CAN bus of the car, yet, so I figured the AMP is not hooked up, and hence, no audio.

 

CAN isn't needed for audio to work. You just need the correct plugs from the HU connected to the Fiber Optic box, power and ground to the FOB, and the fiber optic leads from the car plugged into the FOB. Some pics would definitely help.

 

OK, no Fakra or other connector comes up to the unit in my car. Guessing it's all in the trunk, and that I will need to run a new cable to the front. I do have this three pin connector, which has a clear covered wire in the center. Could be a ground there, could be signal, I suppose. Fiber Optic box has power. Can Decoder has this molded connector that makes it seem that it should connect to the main COMAND connector, but it appears to be CAN, and the original connector is power, ground and ?. I have looked at numerous wiring diagrams online, and none seem to completely line up with this car.

CD changer is still in the car. Do I need a loopback for the fiber optic cable going to it?

 

Are you planning to keep the CD player?

I don't whenever I get around to this once my car is back. On my G wagon I didn't worry about the antenna being connected. I would have liked it to orig but then realized since I was mainly wanting Carplay and such to play my music via stream. I did try to make the antenna work but then realized I could simply use the I Heart Radio app to get all local radio stations plus across the US, I then gave up on it working. I would simply bootup quickly and by the time I was in reverse it was loaded back to last used app and streaming.

 

I don't have any plans to use the CD changer, and I like the idea of converting it to the secret compartment.

I could skip the radio, and I might for now, but I like things to work properly, even if I don't plan to use them too often.

 

Yes, you would need to run a cable from the trunk antenna connection forward to the HU. I routed mine up the driver's side. It takes a while, but installs cleanly if you end up doing it.

I cannot tell from the pics. What RCA leads do you have connecting the HU to the FOB? I see one that says "front", but I cannot read the other. On mine, it needed to be the AUX outputs. The FOB does not allow for front/rear signals. It only supports left/right signals.

It also looks like you have the constant +12 and switched +12v leads tied together on the FOB. That isn't correct. They are separated for a reason. Maybe I am not seeing it correctly in the pics.

 

I have the +12v and ACC separated on the radio, but I should look at the FOB again. That portion was already wired when I got the setup. Again, it was all used stuff, but was installed in another W211. The year to year differences seem to be greater than I would have thought.