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Del Cecchi Del Cecchi is offline
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First recorded activity by BoatBanter: Aug 2006
Posts: 77
Default Testing power trim tilt relays


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On Sat, 25 Oct 2008 15:23:52 GMT, "Chuck" wrote:

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


Bear in mind, this is only true of the newer outboards. The early
90s
Mercs now sold as "classic 2 stroke" use regular spst starter
solenoids for up and down. They are not interlocked through normally
closed points.


They use repackaged automotive accessory relays. Starter Solenoids
are a totally different thing, often integral to the starter these
days although I am not sure if Ford switched from the ones mounted
near the battery.