Chrysler 100, 115 and 140 HP Outboard Motors Service Manual, OB 3439, Page 79Get this manual
When indicator knob is at full clockwise positionmark on knob must line up with100" mark on coverIf it does not, adjust knob NOTE
CReset indicator circuit by pressingRESET" button Indicator light should go out
If indicator light does not go out after pressingRESET" buttonproceed no furtherC-O unit is self-triggering and should be replaced DCycle test button minimum of times Indicator light must go on every timeIf light does not go on every timeC-D unit is intermittent and must be replaced