Hey guys I haven't come across these factory service manuals on this forum yet so below I've got links to FSM for Imprezas. Wiring diagrams included. Also have a few for certain Legacy and Forester models. Should save us the effort of browsing other forums.
http://ken-gilbert.com/page/3?s=impreza+manuals&x=18&y=14
http://forum.wrx.com.au/viewtopic.php?t=45443