underneath the faux tank you have found the regulator/rectifier on the ouside of the frame rail. on the inside of the rail, closer to the fuse box (on my 82 anyway) is a small 2 prong little box. that should be the seleniunm rectifier and is connected inline between the switch on the clutch and the starter solenoid. it is also operates the neutral light. it's so when you pull the clutch in and the bike is in gear it will start but wont start with the clutch out unless it's in neutral.