Mercury Mariner V-250 V-275 Outboard Service Shop Manual 1990, Page 311Get this manual
Power Trim Electrical Connections ""WARNING
00 not electrically operate the power trim pump out having the pump hoses connected to the outboard Hydraulic pressure will force shipping caps off ends 01 pump hoses
1In stall wiring grommet into opening in transom side of inlet cover2Rou te blue and purple sleeved wires from remote control, up Ihru wiring grommet of inlet cove and make connection, as shown
IMPORTANT: The Power Trim electrical system is pro tee led by 90 amp fuse and 20 amp fuse(Both mounted on the power trim pump If the Power Trim electrical system becomes inoperative, check for blown fuseIf fuse has blownthe cause lor overload MUST BE found and corrected BEFORE replacing the fu se