Peugeot wiring diagrams are available in a software package called the SEDRE. It is a sort-of interactive, functionally-based collection of diagrams and illustrations. Once you have learned to drive it, it is very good.
It is usually packaged with the Service Box Documentation, which gives parts information and repair procedures.
The best way to get it is here. Although it looks as if you are buying the package for a particular model, it actually covers all the listed models. It is very easy to install, the instructions are excellent, and it's the best tenner I ever spent.