http://www.youtube.com/watch?v=bOBEQqsSOtA

Does the electric trim and tilt pump motor not move at all? Does the
electric trim and tilt pump motor only run in one direction, that is, only
up or only down?

IMPORTANT: The engine outdrive trim tilt pump motor will work only if BOTH
relays are connected. This is because power to the trim-tilt pump motor is
in series with BOTH relays. When you activate either relay by pressing the
tilt switch up or down, the internal solenoid becomes energized (you should
hear the relay click) and the ground contact is broken and replaced by a 12
volt input (terminal 87 - thick red wire). The direction that the pump runs
is determined by the direction of the current flow through the relays. (See
diagrams)

When replacing relays, always replace both at the same time. If you have
installed new relays and the trim/tilt pump motor still won't run, there is
obviously a problem with the wiring from the sockets at the base of the
relays. Remember this: CORROSION between the male relay terminals and the
female relay terminal socket is the biggest problem. CORROSION inside the
quick disconnect plugs is also highly suspect.

The up and down relays are identical, so switching them back and forth is
OK. When switching the relays, see if the problem changes directions.

To test the motor itself, bypassing the relays and relay wiring, find the
two heavy gauge wires that lead to the trim/tilt pump motor. One should be
green and the other blue. You will probably be able to find a quick
disconnect plug near where the wires exit the outboard engine cover that you
can disconnect. Ground one wire to any metal surface and provide +12 volts
from the battery to the other. The motor should run in one direction or the
other. Now reverse the wires and the motor should run in the other
direction. This will at least tell you if the motor is operating, so that
you will have a better idea of what the actual problem might be. You can
also pull out a relay (one at a time) and place a temporary wire jumper
inside the relay socket across terminal 87 (the +12DC input voltage source)
and terminal 30 (the outgoing wire to the trim/tilt pump motor) to make the
motor run. It is worth repeating he The voltage and current flows
through BOTH relays, therefore when testing be sure you have a complete
circuit.

Pertains to a Mercury Outboard. I have the larger jpeg wiring diagrams if
anyone needs it.

Chuck