Mercury 35/40HP 2 Cylinder Outboards Service Manual PN 90-42794--1, Page 218Get this manual
Troubleshooting the "Down," "Up" and "Trailer" Circuits (All Circuits Inoperative) Remote Control Equipped with Trailer ButtonBlown Fuse:
Replace fuse
Check two in-line fuses (under cowl) to see if fuses are blownI
Fuses Not Blown:
Connect Voltmeter red lead to Point and black lead to groundBattery voltage shou ld be indicated
Correct prob lem that caused fuse to blowNo Voltage Indicated:
Check battery leads and red leads (between engine starter motor solenoid and Point 3) for poor connections or open circuits Check battery chargeI
Battery Voltage Indicated:
Connect voltmeter red lead to Point 10 Depress "Trailer" button and check for battery voltage
Battery Voltage Indicated: