Head unit wiring problems

[93civicsi]

I took the Headunit out of my dc5r because its rooted and has no usb.
Upon taking it out i found someone has cut,snipped rewired into other wires.

I Bought a Sony headunit and tried just matching up the older wires but it doesnt work........
I have nowhere to plug my accessories into??

In the past i've done a few stereo installs but this one has me stumped.

Eg, the green wire and the earth soldered together? Whats the green wire for?

[Karl]

I took the Headunit out of my dc5r because its rooted and has no usb.
Upon taking it out i found someone has cut,snipped rewired into other wires.

I Bought a Sony headunit and tried just matching up the older wires but it doesnt work........
I have nowhere to plug my accessories into??

In the past i've done a few stereo installs but this one has me stumped.

Eg, the green wire and the earth soldered together? Whats the green wire for?

By earth i assume you mean ground?

Easyest way is to get both wirering diagrams of thr old deck and the new one to compare colours and what they do. Aftermaket decks genrally use thr same colour code

Or use a multi meter to find permant pos , sw pos and ground. And a 9v battery to find what cables do what speeker. Just touch the cable on the battery and listen for buzzing.