1991 Johnson/Evinrude Models "EI" 40 thru 55 Service Manual, Page 129Get this manual
Ohmmeter TestKey Switch
All ohmmeter tests must be performed with the engine NOT running1Install emergency stop switch clip and lanyard assembly1sl2Calibrate ohmmeter on appropriate scaleConnect meter leads between engine harness blackyellow lead and clean engine ground Key OFF, meter must show low reading Key ON, meter must show high reading 3If Step 2, Key ON reading is low one, disconnect harness blackyellow leads from key switch "M" terminal If meter now shows high reading, test key switchRefer to Electrical Section If meter shows low reading, go to Step 44Separate emergency stop switch lead from harness black yellow lead at key switch If meter now shows high reading, test emergency stop switch If meter shows low reading, test wiring harness5If engine fails to shut off, test for open blackyellow lead, damaged key switch, or damaged ignition module6Complete all circuits disconnected during this test