Permanantley Live 12V Socket

cemerson

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I know there are some on here who wanted this, as by default the 12V socket only comes on with the ignition - but it turns out it's very easy to make it a 'permanent on' socket.

I discovered this completely by accident while wiring in my dashcam today. The fuse for the cigarette lighter is apparently movable depending on which option you want (I think Peugeot do this too, I have heard anyway). I haven't actually tested this myself however, but only discovered the functionality while poking around the fusebox with a multi-meter today.

Here's a picture of my fusebox, which can be found by removing the panel at the back of the glovebox - there's a finger hole there to make it easy:

20140316 1058221

If you look just to the right of the 2 15A fuses (the blue ones), you'll see a 20A fuse (yellow) that seems to be going between 2 rows of fuses. I looked up the fuse in the manual to see what it was, and it's the fuse for the lighter socket / 12V socket. The reason for this is because the fuse can be moved depending on whether you want 'on with ignition' or 'on permanently' mode for the the socket. As it's shown there, it's in its 'default' place of on with ignition only, but if you were to move it up half a fuse-length to be in line with the 30A and 40A fuses on the row above, it would be permanently on. I've confirmed with a multi meter that the contacts above the fuse are permanently on and the lower one (the one that the bottom of the fuse is currently in) is on with ignition only. The middle contact (that the top of the fuse is currently in) goes to the socket itself.

Like I say - I haven't actually confirmed it 'end to end' as it were (as I have nothing to plug into the socket anyway!), but I hope someone finds this useful. It's certainly an undocumented feature!
 
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That could also be useful for wiring my TomTom although I have seen a post of the Mk7 GTI Forum which suggests using fuse number 48. It's also nice to know you can get access to the fuses without, as the guy on the GTI Forum suggested, dropping down the opening part of the golve box.

That's what I like about this forum. Some one is always coming up with very useful information and passing it on.
 
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Just a quick note, as nobody had actually confirmed this works: I finally got around to trying it at the weekend and it works a treat - no longer do I have to switch the ignition on to pump up the tyres!
 
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Just a quick note, as nobody had actually confirmed this works: I finally got around to trying it at the weekend and it works a treat - no longer do I have to switch the ignition on to pump up the tyres!

That's great. I can now use it for my tyre pump and my electrical cool box I use when we go on long journeys.

I mentioned this the an Audi Master Tech at my dealer last week and he was interested as he said he is often asked if there is any way to make the sockets permanently live as the used to be on all previous A3s. He didn't know about this method of doing it so that's one up for Camerson and the 8V forum.
 
Oh great... now the pics on this thread have disappeared! What is it with this forum and pictures?!
 
Oh great... now the pics on this thread have disappeared! What is it with this forum and pictures?!

So by moving this fuse it will make both the Cig lighter socket below dash and the 12v socket in boot both live permanently? Very handy.
 
Not sure about the one in the boot
 
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Very cool find! The boot one would actually be more useful as, when away from home and you need to charge phones or batteries or whatever, if you can leave things out of sight in the boot on charge it'd be extremely handy.
 
Yep the one in the boot would be very helpful to me.
 
Very cool find! The boot one would actually be more useful as, when away from home and you need to charge phones or batteries or whatever, if you can leave things out of sight in the boot on charge it'd be extremely handy.

Yes much better to use the socket in the boot for charging a laptop or tablet as this keeps it out of site. Not the sort of things you want to leave on show inside the car. I do that with my current 8P and now I will be able to do the same with my new 8V.
 
Just moved the fuse on my S3 works a treat. Ideal for the summer. Cool box in boot. Anyone know what Audi Uk make of this 'mod'?
 
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I can't see that it would be an issue. Why provide such an easy option if they didn't want anyone to do it?
 
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I can't see that it would be an issue. Why provide such an easy option if they didn't want anyone to do it?

They may not have banked on the cleverness of people on ASN! :)

Only thought from me would be whether it might somehow drain the battery but i assume only if the leave some connected to complete the loop? What about electrical/fire risk, assume negligible?
 
They may not have banked on the cleverness of people on ASN! :)

Only thought from me would be whether it might somehow drain the battery but i assume only if the leave some connected to complete the loop? What about electrical/fire risk, assume negligible?

Possible Audi being ultra cautious by no longer leaving the sockets live. I understand the sockets working through the ignition only has been the standard with VWs for some years. Probably a bit like the notices on the passenger sun visor or some new EU directive.

All the eight A3s I've had so far have always had the sockets permanently live and have never given any problems.

I wonder if it's different between smoking and non-smoking. I suppose with a permanently live cigarette lighter a child could press it in and then take it out and burn itself.
 
It's probably just a precaution to stop people flattening their battery by leaving high-drain devices connected, such as a cool box in the boot.
 
They may not have banked on the cleverness of people on ASN! :)

Only thought from me would be whether it might somehow drain the battery but i assume only if the leave some connected to complete the loop? What about electrical/fire risk, assume negligible?

I would have thought the fire risk was low, after all that's what the fuse is there to protect against!
 
I have just changed the fuse position on the new 8V I collected this morning and it certainly works. All three sockets are now live all the time. Just as they used to be on all my previous A3s.
 
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I have just changed the fuse position on the new 8V I collected this morning and it certainly works. All three sockets are now live all the time. Just as they used to be on all my previous A3s.

Hope you have advised your insurance company.. change from standard spec. ;-)
 
Standard spec is a fusebox that allows you to choose one of 2 positions :p

Do you inform your insurance company every time you move a switch from a position it came from the factory in?
 
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Hope you have advised your insurance company.. change from standard spec. ;-)

Did you when you fitted your roof bars - changed from standard spec. At least mine is an Audi fuse!!
 
Did you when you fitted your roof bars - changed from standard spec. At least mine is an Audi fuse!!

Dave --- chill mate... as Oscar Wilde said....

Shrimp Salad Circus: life is too important . free poster

BTW My Insurer is fully aware that I now have Audi approved roof bars and the cover is in place. Same story when towing boats etc.. third party cover should boat/shed/roof box cause any issues. ;-)

Hope your new 'designer' Tom Tom mod works OK in the 21st Century Audi.
 
Standard spec is a fusebox that allows you to choose one of 2 positions :p

Do you inform your insurance company every time you move a switch from a position it came from the factory in?

I could find no Audi reference to this mod. Where is It? If there is that would allay any fire/non-insured fears.
 
Fuses are user-replaceable, it's in the manual - not this specific mod, but the idea of moving fuses around. What fire risk is there? That's what the fuse is for!
 
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I could find no Audi reference to this mod. Where is It? If there is that would allay any fire/non-insured fears.
I have not seen anything from Audi about this particular fuse. At a guess it is done in this way to allow Audi to cover countries obsessed with Health and Safety where poor little kiddies may burn their fingers when left alone in the car if the car is fitted with a cigarette lighter that is permanently live and those who take a more sensible approach. It also allows both Audi and VW to use the same fuse board. VW have always had their 12v sockets only working through the ignition whereas Audi have, in the past, always had them permanently live. All my previous eight A3s had permanently line 12v sockets and none of them caught fire.

In the current fuse box there is just this one fuse position that has three slots for a two bladed 20 amp fuse. Fuse in centre and bottom slots - 12v sockets work through the ignition. Fuse in centre and top slots - 12v sockets permanently live - simple answer.

And Yes my 'designer' TomTom installation works just as I expected. It was something the technician I spoke to a my dealers said he had already done many times for those customer who prefer the greater flexibility of the TomTom over the in-built Audi system. Again giving the customer the choice which Audi are very good at.
 
Probably also to stop them having to deal with muppets who abuse it and flatten their battery
 
I had a Tom Tom 930T Europe a few years back and found it a real faff and inaccurate. + I do not have a fetish for rubber suckers, wires everywhere, charger, aerial etc and frankly the Audi system is pretty cheap now and no faff. Camera stuff on iPhone if I need it.

On the Health and Safety issue IMHO too many people have fallen for the brainwashing rubbishing the subject. Most advice is well founded and appropriate risk assessments determine its usefulness. 2 year old kid left alone in car with live 12v is foolish by any standards !
 
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I had a Tom Tom 930T Europe a few years back and found it a real faff and inaccurate. + I do not have a fetish for rubber suckers, wires everywhere, charger, aerial etc and frankly the Audi system is pretty cheap now and no faff. Camera stuff on iPhone if I need it.

On the Health and Safety issue IMHO too many people have fallen for the brainwashing rubbishing the subject. Most advice is well founded and appropriate risk assessments determine its usefulness. 2 year old kid left alone in car with live 12v is foolish by any standards !

My TomTom is much older than the 930T and much cheaper when I bought it back in 2008. I've not used the 930T but from what I've read it not the sort of device I would buy. I don't have any aerial wires or chargers visible and only about 75mm of wire from the A-pillar to the device. Everything else is hidden behind the dash panel. Being able to add mu own POIs other than speed cameras is also important as quite a lot of the places I visit do not even have a postcode. Also I don't even posses a smart phone let alone carry one with me in the car so I could not use that for speed cameras.

The great thing about Audi is they give us a choice. As I'm never likely to leave a 2 year old kid in my car alone I can choose to have my socket permanently live. If I did leave young children alone in my car I may well decide to leave the sockets live through the ignition. To me having the sockets always live, as Audi have done ever since the A3 first came out, is the better option and the one I'm used to. Others can have there's how the like.
 
Don't suppose anyone knows if the same fuse covers the USB charging socket (with Audi Connect)?
 
I was wondering the same myself but I don't know I'm afraid. Check the manual to see if there is a separate fuse for it (they're all listed)
 
I think when I tested mine it went off after 10 minutes, like the MMI does. This is the separate charging socket, not using the AMI lead.
 
I forgot to check the manual! Will look tomorrow (again, if I remember)
 
Thanks guys, I was hoping that it stayed live all the time (or at least had the option to via the fuse trick).
 
The online manual lists fuse no. 40 as being for "Cigarette lighter, electrical sockets", and there is no separate reference to a fuse for the USB power socket, so fingers crossed...

Fuse layout