Mercury 35/40HP 2 Cylinder Outboards Service Manual PN 90-42794--1, Page 203Get this manual
3Inspect field and frame assembly as follows: aUse an Ohmmeter (Rx1 scale) and check for full continuity between green (motor) wire and black field wire, and between blue (motor) wire and black field wireIf meter indicates no continuity or high resistance, replace field and frame assembly bUse an Ohmmeter and check for no between black field wire (a) and frame (b) 11 meter indicates continuity, replace field and frame assembly
Brush Replacement
1Brush replacement is recommended if brushes are
aBlack Field WireMotor Wire
pitted, chipped or worn to less than 14 in(6.4mm) If necessary, replace brushes as follows :