led scanner

Hi, I know this is not the first topic on this issue but I can't find any thread that really answers my questions.

I've paid someone to install an old Varad led scanner but the guy has botched the job and he tapped both the black and yellow wire on the same constant 12V wire.Now, I've just bought a new scanner from Varad, the new model and I'm trying to install it by myself. I know exactly where a ground wire and a constant 12V wire are obviously but I have no idea where to find a positive 12V (when the key is in the ignition)...I own an Honda Civic LX 2003 and I don't have any alarm system.Here's a picture of the ground and constant wires. (sheaths are cut) They're located right under the steering wheel but I don't know what they're connected to exactly.

Can someone give me any help or any hints of where to connect the yellow wire of the scanner exactly ?Thank you.

The white wire you tapped into is the constant 12V source to your ignition, and the WHITE/ red wire is the second accessory wire. I don't know where you got the idea that one of these is a ground. I am assuming that you are wanting the LED scanner to be turned on while the car is turned off. The best way to accomplish this will require the use of a relay connected as stated below: 86: Accessory Wire (WHITE/ Red - in ignition harness you have already tapped into) 85: Ground (find a good metal place to ground wire) 87a: constant 12V (White wire you have already cut into) 30: to the (+)12V scanner wire Obviously, ground the 'ground' wire of the scanner. The relay configuration above will give a 12V source to the scanner when the car is turned off.