Bluetooth (Connects2) unit dropping out - earthing fault?

S

sailesh

A2OC Donor
Hi folks - like many of you, I have a Connects2 unit to add Bluetooth connectivity and hands free to my head unit (a Sympony II). Frustratingly, while driving, my unit randomly disconnects its Bluetooth connection, caused by the power cycling on and off in an instant.

I suspect this is an earthing fault, but despite relocating the earth wire to different points of the head unit, I have had no luck resolving the issue. Is there an alternative earthing point I should try, or another potential resolution?

To confirm, when the Connects2 randomly power cycles, it is not accompanied by any power cycling of the head unit (i.e. the problem is limited to the Bluetooth unit). I also don’t seem to have any poor earthing symptoms with the rest of my car’s electronics, but happy to double-check if necessary. I can also confirm that trying a new Connects2 unit (which will soon be on sale) did not resolve the issue. While my unit is stored in the ashtray and does get fairly warm, these symptoms happen right from the outset of a drive, so I suspect nothing to do with overheating.

Any help much appreciated, especially as I will soon be embarking on a 5 hour drive and want to listen to more than repeated “Bluetooth disconnected” prompts!
 
Seems a bit odd to have a separate 0V, (earth), when there is one on the radio. Having 0V, for the same device, in different places is generally, not good practice.
Mac.
 
PlasticMac said:
Seems a bit odd to have a separate 0V, (earth), when there is one on the radio. Having 0V, for the same device, in different places is generally, not good practice.
Mac.
Click to expand...

This is how the connects2/xcarlink is configured for VAG installations - presumably because there isn’t an earth via the pins. In any case, ideas please?
 
Hi Sailesh
For a a bit background is this something you have just installed and it’s been power cycling from day one, or has it been installed for a while and developed this fault having been OK previously?
 
sailesh said:
This is how the connects2/xcarlink is configured for VAG installations - presumably because there isn’t an earth via the pins. In any case, ideas please?
Click to expand...
Does your radio look like this?
Mac
Screenshot_20230603-154738.png
 
All these adapters need a good earth connected to their earth pin. I do not like using the radio chassis as the connection can be poor. Extend the lead if needed and bolt directly to body ground.
 
audifan said:
All these adapters need a good earth connected to their earth pin. I do not like using the radio chassis as the connection can be poor. Extend the lead if needed and bolt directly to body ground.
Click to expand...
Why do they need a separate earth?
Mac.
 
I did not design these units, but the manufacturer who has decided dedicated earths are a requirement. Either for cleaner signal or to be mounted further away to prevent interference I suppose?

In all cases if the earth is not connected the unit does not work.
 
audifan said:
I did not design these units, but the manufacturer who has decided dedicated earths are a requirement. Either for cleaner signal or to be mounted further away to prevent interference I suppose?

In all cases if the earth is not connected the unit does not work.
Click to expand...
I'm curious why, when there's a very good +12, & 0V, (earth) on the radio CD connector, the device uses a separate earth, which could very well create an earth loop.
Mac.
 
audifan said:
All these adapters need a good earth connected to their earth pin. I do not like using the radio chassis as the connection can be poor. Extend the lead if needed and bolt directly to body ground.
Click to expand...

Thanks - any recommendations on where the nearest / most convenient body earth point would be? I suppose I would extend the earth on a temporary basis to hopefully solve the issue, before routing it more permanently.
 
birtyA2 said:
Hi Sailesh
For a a bit background is this something you have just installed and it’s been power cycling from day one, or has it been installed for a while and developed this fault having been OK previously?
Click to expand...

Thanks for asking - it’s been intermittent since day one (which was a couple of years ago) and seems to be more of an issue more lately. I used to get two or three dropouts on a typical journey and now it’s pretty much double digits. Sometimes I can drive for an hour with no issues but other times it’s barely a minute.

Initially I thought the issue was Bluetooth dropout caused by signal interference from nearby cars, but observing more closely it’s clear that the power from the unit is cycling at the same time that the Bluetooth drops out. This is evidenced by my phone - which is being charged via USB from the unit - power cycling concurrently as though being taken on and off charge. I actually bought a second unit and this, unfortunately, has exactly the same issues.
 
sailesh said:
Thanks for asking - it’s been intermittent since day one (which was a couple of years ago) and seems to be more of an issue more lately. I used to get two or three dropouts on a typical journey and now it’s pretty much double digits. Sometimes I can drive for an hour with no issues but other times it’s barely a minute.

Initially I thought the issue was Bluetooth dropout caused by signal interference from nearby cars, but observing more closely it’s clear that the power from the unit is cycling at the same time that the Bluetooth drops out. This is evidenced by my phone - which is being charged via USB from the unit - power cycling concurrently as though being taken on and off charge. I actually bought a second unit and this, unfortunately, has exactly the same issues.
Click to expand...
Could be that your phone is taking more power than the adapter can supply, while running the device itself. You'll probably find that the USB is only for memory.
Try it with the phone not plugged in for a while.
Mac.
 
PlasticMac said:
Could be that your phone is taking more power than the adapter can supply, while running the device itself. You'll probably find that the USB is only for memory.
Try it with the phone not plugged in for a while.
Mac.
Click to expand...

The USB is definitely intended for charging - below is the unit I have. My setup has the USB powering a wireless charger, which by design most likely has a fixed power draw. However, I will experiment with/without the USB plugged in to see if this can help isolate the issue.

www.xcarlink.co.uk

iPod CD changer adapter, VW iPod, Apple Carplay, Android Auto Music Link are available at xCarLink – the best place for all of your iPod car linking needs.

www.xcarlink.co.uk www.xcarlink.co.uk

As regards earthing, the Xcarlink installation notes merely state:

“Audi, VW, Seat and Skoda:

Additional Ground cable included (black wire with ring connector). This needs to be connected to a suitable earthing point i.e the body of the stereo.”

iPod CD changer adapter, VW iPod, Apple Carplay, Android Auto Music Link are available at xCarLink – the best place for all of your iPod car linking needs.

www.xcarlink.co.uk www.xcarlink.co.uk

So, at least a couple of options to investigate...
 
PlasticMac said:
Does it still power off and on, when nothing is connected to the USB socket?
Mac.
Click to expand...
The reason I'm asking this is because I don't think it's an earth problem.
I think it's a power problem. Maybe the circuit with in the radio, that powers the CD changer, (where the adaptor is connected), is current limited, at a level that the changer would draw, and simply cannot supply the adaptor, and your phone charger. You can prove or disprove this by running with nothing in the USB socket.
Mac.
 
sailesh said:
I want to listen to more than repeated “Bluetooth disconnected” prompts!
Click to expand...
Hi Sailesh,

The very fact that you hear "Bluetooth disconnected" means that the Bluetooth dongle is still alive and connected to the stereo. This effectively rules out an earthing fault. If the connection to earth was poor, the Bluetooth dongle would lose its wireless connection to the phone and its wired connection to the stereo.

PlasticMac said:
The reason I'm asking this is because I don't think it's an earth problem.
I think it's a power problem. Maybe the circuit with in the radio, that powers the CD changer, (where the adaptor is connected), is current limited, at a level that the changer would draw, and simply cannot supply the adaptor, and your phone charger. You can prove or disprove this by running with nothing in the USB socket.
Mac.
Click to expand...
Based on what I've read so far in this thread, I'm inclined to agree with Mac's assessment of the situation.

The USB port on the Connects2 unit doesn't have a data connection; it just provides a 5V output for charging purposes. However, the Connects2 unit is attached to the CD changer port on the back of the stereo head unit, which has very limited current-giving capability. A large portion of the available current is used by the Connects2 unit itself, meaning that very little remains for charging purposes. Indeed, when I used to have one of these units in my A2, I found that the unit really struggled to charge phones with older batteries, or batteries that were very cold or already very depleated. This problem will be further exacerbated in your case by the use of a wireless charger (with its inherent inefficiency). As such, I often install a dedicated high-current USB socket in conjunction with the Connects2 unit, but connected to an alternative power source.

I'd do as Mac suggests; test whether the Bluetooth connection holds stable when there is nothing connected to the USB port.

Cheers,

Tom
 
Last edited:
timmus said:
Hi Sailesh,

The very fact that you hear "Bluetooth disconnected" means that the Bluetooth dongle is still alive and connected to the stereo. This effectively rules out an earthing fault. If the connection to earth was poor, the Bluetooth dongle would lose its wireless connection to the phone and its wired connection to the stereo.


Based on what I've read so far in this thread, I'm inclined to agree with Mac's assessment of the situation.

The USB port on the Connects2 unit doesn't have a data connection; it just provides a 5V output for charging purposes. However, the Connects2 unit is attached to the CD changer port on the back of the stereo head unit, which has very limited current-giving capability. A large portion of the available current is used by the Connects2 unit itself, meaning that very little remains for charging purposes. Indeed, when I used to have one of these units in my A2, I found that the unit really struggled to charge phones with older batteries, or batteries that were very cold or already very depleated. This problem will be further exacerbated in your case by the use of a wireless charger (with its inherent inefficiency). As such, I often install a dedicated high-current USB socket in conjunction with the Connects2 unit, but connected to an alternative power source.

I'd do as Mac suggests; test whether the Bluetooth connections holds stable when there is nothing connected to the USB port.

Cheers,

Tom
Click to expand...
Wireless charging is also very inefficient, draws nearly twice as much power than goes into the phone battery.
Mac.
 
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