2001 Mercury Mariner 50-60HP Factory Service Manual, Page 319Get this manual
POWER TRIM
TRIMMING OUTBOARD "DOWN" ("IN")
WARNING
Excessive speed at minimum trim "In" may cause undesirable andor unsafe steering conditionsEach boat should be tested for handling characteristics after any adjustment is made to the tilt angle (tilt pin relocation) Will help planing off, particularly with heavy loadUsually improves ride in choppy waterIn excess, can cause boat to veer to the left or right (bow steer)Transfers steering torque harder to right (or less to the left)Improves planing speed acceleration (by moving tilt pin one hole closer to transom)
Operating "Down" circuit will actuate the "down" relay (located under engine cowl) and close the electric motor circuit (motor will run in opposite direction of the "Up" circuit)The electric motor will drive the pump, thus forcing automatic transmission fluid through internal passageways into the "down" side of the trim cylinderThe trim rod will move the engine downward to the desired angle