12v socket power

[Dreque]

Ive been installing a new stereo and I've come across and extremely strange problem with the 12v ciggarette lighter socket. It's normally powered like so, Purple = 12v, Black = earth and the yellow one I'm not sure. Anyway during this new installation with only involves putting adapters on, the live wire for the 12v socket is now the yellow cable which doesn't even connect to the ciggarette socket. I installed the old radio back and it's still wrong. I'm an electrician and work on aircraft so I'm pretty aware of any silly basics and I'm so perplexed as to how this has happened. No wiring has actually been changed, yet now the cable with a live feed has just suddenly switched over

[Mo_miah]

which cigarette socket are you connecting to? guessing the 3rd wire is for illumination
also why are you connecting to the cigarette lighter socket? changing a stereo shouldn't need it
bit more info on what you are trying to achieve would help

[Dreque]

I'm not trying to connect anything to the front ciggarette lighter. I have a dash cam wired to it and noticed it stopped working. Measured it with a multi meter and sure enough the live wire is now the yellow cable and not the purple. All I've done since it switching was fit a radio. But like I said I've not rewired anything. Went back to stock and the problem persists.

[umfaan]

If you are connecting any Dash Cams etc to the Gigar lighter I would recommend you Down grade the Fuse ,as the Gigar lighter would have a high amp rated fuse to accomadate it .....unless you are sub fusing of this feed.

[Lff64]

Just wondering if you have popped a fuse whilst changing things around , I would unplug/ disconnect the dash cam and test again between purple - Black for 12V (ignition on) . As stated I think yellow is for illumination but just not used

[sriray]

Live wire is purple
Ground is Black
Autolighting is Yellow

Check if you blown a fuse.