Chrysler 100, 115 and 140 HP Outboard Motors Service Manual, OB 3439, Page 75Get this manual
record the voltageIf there is one (1) volt or more drop in voltage, there is too much resistance in the switch and it should be replaced Test #2C-O Unit (On Engine) Test Equipment 8953 C-O Tester1Check battery voltage at starter relay as follows:
AConnect "BATT P" and "BATT N" test leads from
testerFigure 9Also remove BLUE wire of engine wiring harness from the terminal block to prevent engine from starting
AWARNING
When these test leads are connectedtheC-O IN" test lead from C-O tester isLIVE" Be certain it does not contact any metallic object or sparks may occur and possibly cause ignition of gasoline vapors