Chrysler 75 and 85 HP Outboards Service Manual OB 3646, Page 77Get this manual
NOTE When indicator knob is at full clockwise position, mark on knob must line up with100" mark on coverIf it does not, adjust knob
CReset indicator circuit by pressingRESET" buttonIndicator light should go out
If indicator light does not go out after pressingRESET" button, proceed no furtherC-O unit is self-triggering and should be replaced OCycle test button minimum of times Indicator light must go on every timeIf light does not go on every time, C-O unit is intermittent and must be replaced