I've had my 1988 290 for almost two years and have been searching for an electrical schematic since day one. I've learned that when Aquasport changed hands in the late 80's, most of the data on discontinued models was discarded. I've looked at several 290 tournaments from several different years and I've seen no two alike. I doubt they ever made any detailed manual on the model. Incidently we are very happy with the boat. I've done a lot of work on mine and have become pretty familiar with it. If you have a question about a specific system, I may be able to help you.