Chrysler 70, 75 and 85 HP Outboard Motors Service Manual OB 3438, 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" button Indicator light should go out
If indicator light does not go out after pressing "RESET" buttonproceed no further C-O unit is self-triggering and should be replaced DCycle test button minimum of timesIndicator light must go on every time If light does not go on every time, C-O unit is intermittent and must be replaced