I just purchased a Catalina 22 and have questions about the electrical system. It appears simple - just a master switch, cabin lights, navigation lights, anchor light, and accessories switch. At first, nothing seemed to work, except the master switch and the battery. By examining connections and changing a few bulbs, I was able to get two out of three cabin lights working. I can't understand why the third one doesn't work. And, I have not been able to get the exterior lights to work either. I have tried changing bulbs and examined all the connections at the switch plate with no luck. It seems as though all the wiring is very well concealed through the hull, so I cannot inspect it. Any suggestions on how I can further DIAGNOSE and FIX the problem? Thank you!