Troubleshooting The "Down" And "Up" Circuits (All Circuits Inoperative) - Mercury Optimax 115 Service Manual

Troubleshooting the "Down" and "Up" Circuits
(All Circuits Inoperative)
Blown Fuse:
Correct problem that caused
fuse to blow.
Replace fuse.
No Voltage Indicated:
Check battery leads for poor
connections or open circuits.
Check battery charge.
No Voltage Indicated:
Check that voltage is being
supplied to control by performing
the following checks:
DO NOT start engine.
Turn ignition switch to "Run"
position.
Check for voltage at any instru-
ment, using a Voltmeter.
No Voltage Indicated:
Red wire is open between Point
3 and red terminal on back of
the ignition switch.
Check for loose or corroded
connections.
Check for open in wire.
90-855347R1 JANUARY 1999
Check in-line fuse (under cowl)
to see if fuse is blown.
No Voltage Indicated:
Connect red Voltmeter lead to
Point 5, and black lead to
ground.
Fuse Not Blown:
Connect Voltmeter red lead to
Point 3 and black lead to
ground. Battery voltage should
be indicated.
Battery Voltage Indicated:
Connect Voltmeter red lead to
Point 8 and black lead to
ground.
Depress "Up" trim button and
check for battery voltage.
Battery Voltage Indicated:
Check black ground wires for
poor connection
ground, Point 10.
Pump motor is faulty. Refer to
"Motor and Electrical Tests/
Repair", following.
Battery Voltage Indicated:
Trim switch is faulty or there is an
open circuit in wires (green-white,
blue-white) between trim buttons
and trim pump.
Check trim switch.
Check all trim harness con-
nectors for loose or corroded
connections.
Check for pinched or severed
wires.
Battery Voltage Indicated:
There is an open circuit in wire
between Point 5 and Red ter-
minal on the back of the ignition
switch.
POWER TRIM
or poor
Page 5B-17