How to work out which of my 12V sockets are on leisure vs. starter battery

[haydnw2]

I've read loads of threads about different 12V cigarette lighter sockets being wired up differently depending on what day of the week your van was put together. I've checked ours using a USB charger that has a voltmeter display on it, and it's clear they're in two pairs. The bit I'm struggling with is how to work out which is which. With the engine off and no hookup I get:

- Kitchen 12.8 V
- Dash cup holder: 12.9 V
- Dash top: 13.1 V
- Bench seat: 13.1 V

And with the engine off and mains hookup plugged in I get:

- Kitchen 13.3 V
- Dash cup holder: 13.3 V
- Dash top: 14.7 V
- Bench seat: 14.7 V

In each case, the only other thing switched on was one LED light above the sliding door. Is this enough information to determine which pair is connected to which battery? Is it simply that the dash top and bench are on the leisure battery because they give the biggest change when connected to hookup? Or is it more complicated than that? Thanks!

 

[GrumpyGranddad]

I’ll be interested to know the outcome of this. I was under the impression that the 2 sockets in the front were powered by the starter battery and those in the ‘camping’ area were powered by the leisure batteries.

 

[Emil Silenhag]

Usually the ones in the front cabin is wired to the starter battery, and the ones behind the front seats are wired to the leisure battery.
If you want to test it, put an amp-clamp on the negative lead to the starter battery and then connect a load into one of the sockets you want to investigate. If your amp-clamp showing amps going through the wire you have your answer...

 

[Sad]

I understood it that hook-up does put some charge to the starter battery depending on the charge state of the leisure batteries...

 

[EddieEagle]

Sounds just like mine, as in dash top and rear sockets , except the kitchen one , are wired to leisure batteries
Coin, cup holder and the kitchen one are wired to the engine battery.

 

[WelshGas]

I've read loads of threads about different 12V cigarette lighter sockets being wired up differently depending on what day of the week your van was put together. I've checked ours using a USB charger that has a voltmeter display on it, and it's clear they're in two pairs. The bit I'm struggling with is how to work out which is which. With the engine off and no hookup I get:

- Kitchen 12.8 V
- Dash cup holder: 12.9 V
- Dash top: 13.1 V
- Bench seat: 13.1 V

And with the engine off and mains hookup plugged in I get:

- Kitchen 13.3 V
- Dash cup holder: 13.3 V
- Dash top: 14.7 V
- Bench seat: 14.7 V

In each case, the only other thing switched on was one LED light above the sliding door. Is this enough information to determine which pair is connected to which battery? Is it simply that the dash top and bench are on the leisure battery because they give the biggest change when connected to hookup? Or is it more complicated than that? Thanks!

Looking at those readings, on your vehicle Dash Top and Bench seat are wired to the Leisure Battery.
The others are wired to Starter Battery and picking up the Trickle Charge voltage.

You don't state the year of your vehicle, but on my 2014 but Model Year 2015 ALL the sockets are wired to the Leisure Battery apart from the Dash Cupholder socket. I confirmed this by checking the voltage as you have and also disconnecting the Starter Battery temporarily.

 

[haydnw2]

Thanks all, very helpful. I don't have an amp clamp, unfortunately. I also have no excuse as to why I didn't think of simply disconnecting the starter battery for a few minutes. The van was first registered in April 2015 but various stickers hidden away inside refer to Q3/Q4 2014 build dates.

 

[WelshGas]

Thanks all, very helpful. I don't have an amp clamp, unfortunately. I also have no excuse as to why I didn't think of simply disconnecting the starter battery for a few minutes. The van was first registered in April 2015 but various stickers hidden away inside refer to Q3/Q4 2014 build dates.

The vehicle might well have been built late 2014, but Model Year runs from 1st July to end of following June, so yours is MY 2015, mine registered 1st Dec 2014 is also MY 2015.

 

[WelshGas]

Thanks all, very helpful. I don't have an amp clamp, unfortunately. I also have no excuse as to why I didn't think of simply disconnecting the starter battery for a few minutes. The van was first registered in April 2015 but various stickers hidden away inside refer to Q3/Q4 2014 build dates.

Just be aware the 1 press window up/down function might need resetting.
Press button to close window and hold for 5+seconds. Press button to open window and hold for 5+seconds.
Repear for both sides. All depends how long the starter battery is disconnected.

 

[Hotel California]

Is it not easyer to remove the fuse for the rear battery system ? That way you don‘t need any tools and chance on settings getting lost (radio , ect...)
That will tell what is working from the starter bat.

 

[clarinetbcn]

In my 2014 MY Beach, with a constant voltage readout from the leisure battery with engine off and no EH, a load connected to any 12v outlet will make the voltage go down, except for the cup holder. Conclusion: cup holder outlet runs off engine battery, all others including dash top outlet run off leisure battery.

 

[rod_vw]

Disconnect the leisure batterie(s) and see which ones don't work. Simples.

 

[AlanC]

There is no definitive way these sockets are wired from month to month in the factory.

On my 2010 van the cup drawer socket is powered from the leisure battery as are all the habitation ones. I know other vans have the cup socket switched by the ignition, so powered from the engine battery.

The more definitive method is to pull the relevant individual fuse (blue 15 amp, usually grouped together) under the front passenger seat and check which socket is dead.

Saves guessing voltages or disconnecting the battery and any consequences of that.

Alan

 

[Ch1pbutty]

Disconnect main engine battery terminal, and then plug something into the 12v sockets to see which are working.

(For our 2012 Beach, only the socket on top of the dash is from the engine; cup drawer & others are all off the leisure.)

 

[clarinetbcn]

Disconnect main engine battery terminal, and then plug something into the 12v sockets to see which are working.

(For our 2012 Beach, only the socket on top of the dash is from the engine; cup drawer & others are all off the leisure.)

I wonder if at the Cali assembly plant they have a running bet to see how often they can change the battery hook ups to the 12v sockets without anybody in management knowing. The betting pool for changes in the fuse boxes must be huge.

 

[SimonB]

I wonder if at the Cali assembly plant they have a running bet to see how often they can change the battery hook ups to the 12v sockets without anybody in management knowing. The betting pool for changes in the fuse boxes must be huge.

I had a 180 SE and the 12v sockets were wired up in a very strange way. The one on top of the dash was from the engine battery, the one under the dash was from the leisure battery. The one on the end of the sink was from the engine battery, I had this one changed to the leisure batteries as it was where we charged our phones overnight and didn't want to run the battery down if we stayed in one place for a time. Finally the one under the bench seat came of the leisure batteries.
I eventually did what @WelshGas said above and removed a lead from the starter motor battery. This confirmed beyond doubt that what I've written above was the case. I checked other 180 SEs at meets I went to and there didn't seem to be any logic to it. It does help to make sure as you don't want to run the starter motor battery down and not be able to restart the vehicle. I think removing the lead only affected the cabin heater which needed to be reset afterwards, but that was very straightforward with advice from @WelshGas.

 

[acer]

For those that don't want to disconnect the starter battery / remove fuses, I seem to remember working out the set-up of my 12v sockets by reference to the central display. I plugged a fan in to a socket and then checked the display to see whether it was drawing anything from the leisure battery. If there was no change I assumed the socket was connected to the starter battery.

 

[clarinetbcn]

For those that don't want to disconnect the starter battery / remove fuses, I seem to remember working out the set-up of my 12v sockets by reference to the central display. I plugged a fan in to a socket and then checked the display to see whether it was drawing anything from the leisure battery. If there was no change I assumed the socket was connected to the starter battery.

Yes, as post #11. Easy and without possible secondary consequences of disconnecting anything.

 

[acer]

Yes, as post #11. Easy and without possible secondary consequences of disconnecting anything.

Ah! Yes. Missed that post

 

[haydnw2]

Thanks all, a variety of good ideas here! Given the vagueness of the fuse layout diagram in our handbook, I ended up disconnecting the starter battery, and it seems the cup holder and kitchen are on the starter, and the dashboard top and the bench seat are on the leisure batteries.

 

[SimonB]

Thanks all, a variety of good ideas here! Given the vagueness of the fuse layout diagram in our handbook, I ended up disconnecting the starter battery, and it seems the cup holder and kitchen are on the starter, and the dashboard top and the bench seat are on the leisure batteries.

That's how our T5 was wired up until I had it changed. The kitchen work surface is such a useful place to put phones, etc for recharging that we were in danger of running down the engine battery if we stayed on site for a while. I had an auto electrician change it for me, relatively straightforward as the leisure batteries are both near to the socket.