# Dashcam - fuses provide power after engine off/locked



## Medium (Jul 14, 2019)

Hi all,

I recently got an Audi TT MK3, and I've spent hours trying to fit my dash cam. I found a fuse behind the glovebox which provides sufficient power (F40, the cigarette lighter and electrical sockets fuse).

However, the fuse provides power to my dashcam even after the ignition is off, and the car is locked. I've tried plugging something into the cigarette lighter and then turning the ignition off and locking the car, and the lighter port _still_ provided power. Additionally, I even tried the MMI fuse, and the MMI definitely turns off, and yet its fuse still provides constant power to the dash cam after engine off/car locked.

Is this normal? Why is the cigarette lighter still providing power and charging devices even when the ignition is off and the car is locked?

Cheers!

Edit: Looks like it's normal for the cigarette port to keep providing power after the car ignition is off and the car is locked. Is there any other fuse I could use where this wouldn't happen? i.e. one which turns on/off with the ignition?


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## pcbbc (Sep 4, 2009)

Medium said:


> Is there any other fuse I could use where this wouldn't happen? i.e. one which turns on/off with the ignition?


I think I read somewhere that the empty socket either immediately above or below (I forget which, sorry) the existing fuse is switched.
The person who posted that "simply" moved their lighter socket power to that location, thus making their lighter socket now switched.
Or of course you could fit your own fuse, or piggyback adapter, in that location for the camera and keep the existing permanently powered configuration for the socket.

Edit: My apologies though, that may well have been a MK2.
This thread seems to say F40 *IS* switched.
Did you try with the car locked? Since ignition is now keyless, perhaps that has a bearing on when it is live?

My best guess is it was designed this way so the tyre inflator can be used in an emergency without the ignition being on? I know you could easily just turn the ignition on to the accessory position in that case, but then someone might be daft enough to try to change a tyre with the engine actually running because they didn't realise that? So now Audi can't be sued by some ambulance chasing lawyers claiming their client thought they had to have the engine on...


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## ZephyR2 (Feb 20, 2013)

I had the same problem trying to install a dashcam in my wife's Mini. Turns out that all (that I tried) of the switched circuits stay live for as long as 10 minutes after the car has been shut down and locked up. Probably the same issue on the TT. I do know the USB ports in the centre console stay on for a while and become live again as soon as you unlock the car.
For the same reason my solution was to rig up a test bulb to a likely fuse connection and place the bulb where it can be seen from outside the car. Lock up the car and come back and check on the bulb every few minutes. If after, say, 10 minutes its not gone out then assume that fuse is permanent live and try another.


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## Medium (Jul 14, 2019)

Hey everyone, thanks for the replies!

Posting an update in case anyone else is in a similar situation, hopefully this helps.

I got the dashcam working, the F40 fuse has a single space above and below for the fuse pins. I moved the fuse one space down, which has changed the cigarette lighter to now only provide power when the ignition is on, and not when ignition is off. This means when I now start the car, the dashcam comes on, and when I turn it off, the dashcam goes off with it.

All sorted!

Thanks again!


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## berndv (Jun 29, 2018)

I took the simple option. Instead of messing with the fuses, I got the power-magic-ez accessory from Blackvue, that uses the obd socket.
It has some settings so that you can set how long it should run after turning the engine of. Also it has voltage protection. So that it switches of if voltage goes under a certain level.
It is meant for Blackvue camera's but the output is simple 12v so if your dashcam uses a similar plug or you got the skills to replace the plug with a different one, it can work for other brands too.

https://www.blackvue.com/power-magic-ez/


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## ZephyR2 (Feb 20, 2013)

berndv said:


> I took the simple option. Instead of messing with the fuses, I got the power-magic-ez accessory from Blackvue, that uses the obd socket.
> It has some settings so that you can set how long it should run after turning the engine of. Also it has voltage protection. So that it switches of if voltage goes under a certain level.
> It is meant for Blackvue camera's but the output is simple 12v so if your dashcam uses a similar plug or you got the skills to replace the plug with a different one, it can work for other brands too.
> 
> https://www.blackvue.com/power-magic-ez/


Looks like an easy solution for a reasonable price. However there is some controversy about using the OBD socket for such devices, some say its not advisable. 
This device is manufactured by a reputable company and is designed for this purpose so it should be OK. However one of the worries though is that if something goes wrong with power adaptor, as it is connected to the heart of your car's systems, it could end up frying the ECU.


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