Mercury 35/40HP 2 Cylinder Outboards Service Manual PN 90-42794--1, Page 221Get this manual
Troubleshooting the "Down" and "Up" Circuits (All Circuits Inoperative) Remote Control NOT Equipped with Trailer Button
Check two in-line fuses (under cowl) to see if fuses are blown I
Blown Fuse:
Fuses Not Blown: Connect Voltmeter red lead to Point and black lead to groundBattery voltage should be indicated
Correct problem that caused fuse to blow Replace fuseNo Voltage Indicated: Check battery leads and red leads (between engine starter motor solenoid and Point 3) for poor connections or open circuits Check battery chargeBattery Voltage Indicated: Connect Voltmeter red lead to Point 10 and black lead to ground Depress "Up" trim button and check for battery voltage
Battery Voltage Indicated: Check black ground wires at solenoids for poor conenction or poor ground Check black motor lead for poor ground at Point 12If wire is groundedthe pump motor is faulty Refer to "Motor and Electrical Tests Repair," following
No Voltage Indicated: Connect red Voltmeter lead to Point 5, and black lead to ground