2009 Yamaha F40 Outboard Service Manual, Page 109Get this manual
Checking the electrical componentEngine control units and components
9Install the main relay a, and then connect the main relay coupler a
Checking the engine ECM circuit
12345678 Br b
1Disconnect the engine ECM couplers and b
Test harness (8 pins) b: YB-06879 Battery lead Connect Disconnect 7Connect the positive battery lead to the terminal and the negative battery lead to the terminal g, and then check for continuity between the terminals and dReplace the relay if out of specificationNOTICE: Do not reverse the battery leadsTerminal 2Check for continuity between the engine ECM coupler terminals and the ground39 48