Hi, I was replacing the head unit in my car with a brand new one from Sony. Hooked up all the wires correctly (from what I can tell). Worked okay but then swapped out for a new iso harness. Now when I plug it in the head unit does nothing - no power going to it (doesn't matter which iso I use). The keyless central locking has also gone - I now have to lock each door one at a time. Any ideas?