Unfortunately I had already pulled them out :stupid:
Anyways I put the yellow wire where the red one came from, and the yellow where the red was on the black plug bit. The HU (with some fiddling with the wire) came on the sounded like it was loading the CD, then turned off again.
Every now and then it would load for the same time, then die as before. I don't understand how it stays on for the same time every time if it isn't getting a constant 12v? Is there anyone who can help in the Huddersfield area as it's killing me lol.