[Sprinterman]

Installed a new MMI box and all speakers were working fine. Now I’m only getting one side working, I’ve unplugged the MMI box and all I’m getting from the left side speakers is a loud humming noise with a faint bit of music I’m playing from apple CarPlay. Any ideas anyone? It’s a pretty tight fit when Installed the MMI box and wondering if a quad lock wire has come loose, cds work through all speakers as does the factory DAB radio

[fe7565]

Originally Posted by Sprinterman

Installed a new MMI box and all speakers were working fine. Now I’m only getting one side working, I’ve unplugged the MMI box and all I’m getting from the left side speakers is a loud humming noise with a faint bit of music I’m playing from apple CarPlay. Any ideas anyone? It’s a pretty tight fit when Installed the MMI box and wondering if a quad lock wire has come loose, cds work through all speakers as does the factory DAB radio

I would also check the quadlocks, and check if the (speaker) wires inside are properly seated.

[thatgarrett]

Does your MMI connect to audio via the Aux In port? That sounds a lot like a bad 1/8” jack cable that isn’t making good contact

[Sprinterman]

Thanks for that, speaker wires are find as the radio cd all play correctly through all 4 speakers. It must be a loose quadlock, probably the green wire. It’s not connected through aux, it’s connected via a usb that comes out the back of the MMI box

[Sprinterman]

So I’ve checked the green optical cable it’s seated correctly, did notice some slight damage to the outer plastic holder but the lens seems to look ok. I’m getting these errors on BimmerLink, I’ve cleared them but still no sound from the left side speakers just a humming sound. Any further ideas anyone?

[fe7565]

Did you disconnect and reconnect the quad locks? Green cables not swapped? Aligned properly with light source? What errors come back?

[Sprinterman]

I disconnected the optical socket which goes into the back of the head units MMI quad lock, there are 2 laser lenses in the optical socket, am I right in thinking one is for left speakers and one for the right?

[fe7565]

Originally Posted by Sprinterman

I disconnected the optical socket which goes into the back of the head units MMI quad lock, there are 2 laser lenses in the optical socket, am I right in thinking one is for left speakers and one for the right?

I don’t think so. The fiber optic goes to the instrument cluster and the rear Combox.
Re-connect the quad locks . The entire square piece. Both of them.

[Sprinterman]

I’ll try to reconnect both quad locks, but they are a nightmare to take out, as you can see from the photo (a spare quadlock I have) there are 2 entry points for the optical cable, mine is entered through the left hand side, I’m not sure If the right hand side is the correct side or not, but it was working ok before with it in the left side. Trouble is you won’t know of it works until you connect everything up again.

[Sprinterman]

Solved…that garrett you were right, sometimes it’s the simplest things. I fitted an aftermarket amp 6 months ago and placed it under the glove box 12 volt socket compartment which drops down. The auxiliary plug (which isn’t used) attached to the Amps quadlock was resting against the 12 volt socket, hence all the speaker error codes and the interference, no left speaker issue. Taped up the aux plug now all speakers work. Much appreciate your help guys

[thatgarrett]

Glad it turned out to be something so easy. Once I was helping a friend change his battery and then spent the next 6 hours troubleshooting all kinds of check engine codes, only to discover my friend never tightened the negative terminal when reinstalling- it’s always the simple things we never double check lol

[Sprinterman]

That sounds like a world of pain! These cars are sent to test us right. A guy I know installed an MMI box in his Mini Cooper and blew the 5 amp fuse in the FEM module. He spent a week driving in the summer with his wipers permanently on, no indicators and a host of other issues. Until I pointed out the solution. Thanks again mate