Head Unit Install - Missing Aux Power Line from wiring

[HZRDIZ]

Trying to install a sony head unit into a 1992 Land Rover Discovery - I have all the wires except the Aux wire.

The yellow is the main and it also has an orange companion, which from the factory unit plug are right next to each other, however there is no power feeding through once the key is turned.

I wouldn't imagine this is a fuse as i wouldn't be getting power from anywhere if the fuse was blown.

I have tried all the other misc. wires but to no avail...

The main has a wire splitting off it which is also feeding a constant current but I think this is for the ariel - can i tap the aux from the head unit into this? I would assume this means the stereo would stay on all the time then?

Any ideas what I can do to fix this?

[Alex B]

The aerial wire shouldn't have any current on it. Orange could well be for the dimmer, have you had a look on google or something for a colour code for them?

[HZRDIZ]

I had a bit of a look on google last night but couldnt find anything. I would imagine that it shoudl have an auxilary or could it be something that land rovers didnt have back in early 90s and just had a main connected to it?

[DeeCee]

tap off ignition

[AE82 FXGT]

what he said, just find a wire coming off the barrel that comes on when ign is on acc

[Emperor]

or cig lighter