Android Head retrofit unit volume very low

[AFerreira]

I have an A4 B8 with concert radio and AMI. Bought an Android head unit (7" Android 9.0 PX6 six-core 4G+32G Car Multimedia for AUDI A4 S4 A5 Q5). Plugged in the AMI/AUX cable to the AMI unit and enbaled the AUX port via ODBEleven.
When I play regular radio (via the OEM screen) the volume is fine but when I switch to the additional features of the head unit such as play music from SD card or play video or any other function that requires audio play, the volume is very low, and if I raise the volume to MAX, I can hear the audio very low and a ton of static louder than the actual audio.
Does anyone have any experience with this and might have an idea of what is wrong.

Solution:
So the issue was a ground issue with the harness, manufacturer spliced the ground going to the AMI unit and T'd it to also go to the head unit. Remove the ground cabled going to the head unit at the ground junction in the harness that came with the radio and ground it directly to the car. The AMI ground is on pin 3 on the 12 pin plug (the plug is a 2X6 plug with pin 1 being right audio, to the right of pin 1 is pin 3 which is ground and below pin 1 is pin 2 which is left Audio) there are only three wires on the plug.

If you are interested in the steps that led me to find the solution keep on reading otherwise hope this help's someone.
I went to two audio places to see if anyone one of them could fix the problem but got a big NO on both. Can't really blame them as they did not want the liability. One of them actually told me that they only install new radios, they do not fix problems. Not willing to give up, I went back home and took everything apart again. Once I took out the Tesa tape from the harness, I noticed that the manufacturer of the head unit had spliced the ground wires from both the amp and the the AMI plugs (now that does not look right) since I was having issues with the multimedia of the head unit only (radio, Phone and Nav were good) I removed the ground wire that goes from the AMI plug to the head unit and grounded the head unit directly to the car and BINGO!!! No more crackling or static. All this after spending some time on youtube figuring out what each color wire was, and looking at some videos that mentioned the static and possible problems. It turns out that the wire gauge used for the AMI signal is not big enough to offset the power. I used 16 gauge wire to ground the head unit to the car. Connected the ground wire coming out of the head unit to the 16 gauge wire with a butt connector and then connected the ground wire to a bolt next to the fuse box on the right side of the car, and all was well in the audio.

[AFerreira]

Ok so a little more details.... FM and Sirius radio the sound is fine, Phone call audio is working fine and so is the NAV. the only issue with the static seems to be when I try to play a video or music from my phone.
I have an AMI/AUX cable connected to the AMI unit in the glove compartment which the other end is not connected to anything ( just there to enable the AUX in the concert radio). when I launch the video app or try to listen to music via the Bluetooth the audio is very low and if i raise the volume I start getting static. also when I accelerate the static seems to get louder. On my ODBEleven I get a fault code 03138 which indicates "Input AUX IN: Open or Short to Ground"
Anyone have any suggestions on how to troubleshoot this?
thanks

[TPi]

Solution:
So the issue was a ground issue with the harness, manufacturer spliced the ground going to the AMI unit and T'd it to also go to the head unit. Remove the ground cabled going to the head unit at the ground junction in the harness that came with the radio and ground it directly to the car. The AMI ground is on pin 3 on the 12 pin plug (the plug is a 2X6 plug with pin 1 being right audio, to the right of pin 1 is pin 3 which is ground and below pin 1 is pin 2 which is left Audio) there are only three wires on the plug.

Hi,

first of all great that you also shared the solution for this problem. I am having exactly the same problem with similar setup as you. I read your solution and tried several fixes but still no luck.

So could you please once more describe what you actually changed in the wiring.

Thanks in advance for your reply!

[elscotto80]

Have you asked Daniel for support? There are a few threads here about these units.

Sent from my Pixel 3 using Audizine mobile app