Mercury 35/40HP 2 Cylinder Outboards Service Manual PN 90-42794--1, Page 198Get this manual
Fuse Test 1Use Voltmeter to check for battery voltage at terminal1If no battery voltage is indicated, there is an open circuit between terminal and positive (+) battery terminalBattery voltage must be indicated at terminal before performing next check2Use Voltmeter to check for battery voltage at terminal2If voltage is indicated, the fuse is .KIf no voltage is indicatedfuse is blown Check for and correct electrical short that caused fuse to blow before replacing fuse
Hydraulic Trim Pump Repair
Removing Pump from Boat
1Tilt engine to full up position and engage tilt lock lever2Turn manual release valve clockwise to release pressure from system 3Turn manual release valve full out (counterclockwise) before removing hoses4Disconnect hydraulic trim pump battery leads from battery (negative lead first) 5Loosen trim harness clamp screw and disconnect pump wiring harness connector6Remove hydraulic hoses from pumpCap end of hoses7Install plugs in threaded holes of pump from where hoses were removed 8Remove pump mounting bolts and remove pump