Mercury 40 Service Manual page 339

POWER TRIM
Troubleshooting the Power Trim Electrical System
Refer to wiring diagram on preceding page for location of wire connections.
Problem
Trim Switch "UP" is inopera-
tive, but the Cowl Switch
"UP" does operate.
Cowl Switch "UP" is inopera-
tive, but the Trim Switch "UP"
does operate.
Trim Switch "UP" and Cowl
Switch "UP" are both inop-
erative.
Trim Switch "DOWN" is inop-
erative, but the Cowl Switch
"DOWN" does operate.
Cowl Switch "DOWN" is inop-
erative, but the Trim Switch
"DOWN" does operate.
Trim Switch "DOWN" and
Cowl Switch "DOWN" are
both inoperative.
Trim Switch "UP" and
"DOWN" are both inopera-
tive, but the Cowl Switch
does operate.
Trim Switch and Cowl Switch
are both inoperative.
Trim system operates (motor
runs) without pressing the
switches.
Page 5B-30
Possible Cause
1. Open wire between Wire Connection (1)
and Trim Switch.
2. Faulty Trim Switch.
1. Open wire between Wire Connection (2)
and Solenoid.
2. Faulty Cowl Switch.
1. Open wire between Wire Connection (1)
and the Up Relay
2. Open BLK wire between ground and UP
Relay.
3. Open RED wire between Solenoid and
Up Relay
4. Faulty Up Relay.
1. Open wire between Wire Connection (3)
and Trim Switch.
2. Faulty Trim Switch.
1. Open wire between Wire Connection (2)
and Solenoid.
2. Faulty Cowl Switch.
1. Open wire between Wire Connection (3)
and the Up Relay.
2. Open BLK wire between ground and
Down Relay.
3. Open RED wire between Solenoid and
Down Relay.
4. Faulty Down Relay.
1. 20 AMP Fuse blown.
2. Faulty trim switch.
3. Wire is open between fuse holder and
solenoid.
4. Wire is open between fuse holder and
trim switch.
1. One of the Trim Pump Motor wires is
open between the motor and the Relays.
2. Faulty trim pump motor.
1. The Trim or Cowl switch is shorted.
Remedy
1. Check for a open connection or cut
wire.
2. Replace
1. Check for a open connection or cut
wire.
2. Replace
1. Check for an open connection.
2. Check for an open connection.
3. Check for an open connection.
4. Replace
1. Check for a open connection or cut
wire.
2. Replace
1. Check for a open connection or cut
wire.
2. Replace
1. Check for an open connection.
2. Check for an open connection.
3. Check for an open connection.
4. Replace
1. Replace fuse. Locate the cause of
the blown fuse. Check electrical wiring
for a shorted circuit.
2. Replace
3. Check for a open connection or cut
wire.
4. Check for a loose or corroded con-
nection.
1. Check wire connections (4) for loose
or corroded condition.
2. If voltage is present at connections
(4) when the appropriate trim button is
pressed, then the motor is faulty. Re-
place motor.
1. Replace
90-828631R3 MARCH 1999