I can propose you a workaround until you resolve the issue, or change your phone - maybe there is some compatibility issue, try battery saving mode in the phone while connected.

 

 

If you use Bluetooth you can use a charger from the 12v socket and connect to those apps. Works on my Mk3 pre face lift. Not sure why you "have" to use the USB port. 

Android Auto and Mirrorlink work only through cable connection. Bletooth works only for phone calls and audio streaming. If android auto would have worked wirelessly, it would be great, but it's not possible. Even on the new octavia 4, the connection can be made wirelessly only with apple, android phones still need a cable connection.

20 hours ago, Andrei_Ignea said:

Before making the retrofit I have used a lighter fast charger, with a vent phone holder, because I was using waze on my phone. Just after the retrofit I was foreced to use that usb port for android auto conection. The problem is that android auto is using the phone processor and is draining the phone battery, so it needs a faster charge to keep up the consumtion, at least to keep the phone battery at the same procentage it was when you have conected it to the car.

 

So you don't know how well it worked before the retrofit? It could be faulty. Or the issue could be further up the chain.

Maybe get the tools to remove the screen and head unit to check the cables are all plugged in ok. You will need the tools to remove the screen to gain access to change the usb anyway.

What I'm trying to say is that I have the exact same setup as you with mib2 and old usb socket and don't have any problems. Your problem isn't usb socket type.

12 minutes ago, MarkyG82 said:

 

So you don't know how well it worked before the retrofit? It could be faulty. Or the issue could be further up the chain.

Maybe get the tools to remove the screen and head unit to check the cables are all plugged in ok. You will need the tools to remove the screen to gain access to change the usb anyway.

What I'm trying to say is that I have the exact same setup as you with mib2 and old usb socket and don't have any problems. Your problem isn't usb socket type.

What year is your MK3?

2014

Have you tried using a USB doubler?

 

I can get a USB C doubler..

 

 

Something like this should allow you to charge from an adaptor, whilst you connect the other one to the USB port (in theory).

11 minutes ago, TheWanderer said:

Have you tried using a USB doubler?

 

I can get a USB C doubler..

 

 

Something like this should allow you to charge from an adaptor, whilst you connect the other one to the USB port (in theory).

I don't think this is a solution. I don't need more cables!

Well I've given you a possible solution. You either put up with the problem or try and find a workaround, but it may (or may not) involve an extra cable to supplement the power draw.

The only concern that I have is there maybe an issue with a return current, someone with electronic skills may well be able to confirm or deny that.

 

I have a current draw issue with my S20+ if I want to use AA and Bluetooth, I have to choose one or tother. Not both as I have a wireless charger in the car, which allows me hands free conversations and charging, but it denys me AA. So I just use Google Maps instead, not that I have any need for them UFN. 

My 2019 octavia with amundsen has the same issue. I had been considering using a powered USB hub to get round it, but after reading the advice above, I think I'll try a selection of cables first. I already have the hub, but I'll have to wire up a cable for the power socket as it has a mains adapter that provides 5v at the moment and I would need to convert that to be able to get the power from my cig lighter USB charger. 

Your usb has 4 wires... you need to split a cable behind the dash so that the day lines go to the head unit, and the power comes from the usb charger.

 

The problem with this is that most of the time you need to use the data lines to enable faster charging.

 

So one way or another, you will need to send both lines to both devices.

I am sure this is fairly easily done with the diodes or a relay and a fake load on the head unit. You just need to be able to get both to do so for the data for the power negotiations and then pass it to the head unit.

 

Read the usb specs and lash something up, or use something that already exists potentially with more wires.

I have found that if you have a Baseus wireless car charger and adaptor in the lighter (aka accessory socket), you can then put a second cable into the USB socket and initiate and run AA successfully without any issues. 

 

Now this is all well and good if your phone supports wireless charging. If it doesn't then the only option I can see is to use the port doubler that I have previously mentioned to achieve charging and Bluetooth connectivity. 

 

My S20+ does support wireless charging and when it's in the Baseus charging cradle, it leaves the phones usb port available, so I can connect it to the system via a cable and have a Bluetooth connection at the same time.