Mercury 40 Service Manual

POWER TRIM
Page 5B-30 90-828631R3 MARCH 1999
Troubleshooting the Power Trim Electrical System
Refer to wiring diagram on preceding page for location of wire connections.
Problem Possible Cause Remedy
Trim Switch “UP” is inopera-
tive, but the Cowl Switch
“UP” does operate.
1. Open wire between Wire Connection (1)
and Trim Switch.
2. Faulty Trim Switch.
1. Check for a open connection or cut
wire.
2. Replace
Cowl Switch “UP” is inopera-
tive, but the Trim Switch “UP”
does operate.
1. Open wire between Wire Connection (2)
and Solenoid.
2. Faulty Cowl Switch.
1. Check for a open connection or cut
wire.
2. Replace
Trim Switch “UP” and Cowl
Switch “UP” are both inop-
erative.
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. Check for an open connection.
2. Check for an open connection.
3. Check for an open connection.
4. Replace
Trim Switch “DOWN” is inop-
erative, but the Cowl Switch
“DOWN” does operate.
1. Open wire between Wire Connection (3)
and Trim Switch.
2. Faulty Trim Switch.
1. Check for a open connection or cut
wire.
2. Replace
Cowl Switch “DOWN” is inop-
erative, but the Trim Switch
“DOWN” does operate.
1. Open wire between Wire Connection (2)
and Solenoid.
2. Faulty Cowl Switch.
1. Check for a open connection or cut
wire.
2. Replace
Trim Switch “DOWN” and
Cowl Switch “DOWN” are
both inoperative.
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. Check for an open connection.
2. Check for an open connection.
3. Check for an open connection.
4. Replace
Trim Switch “UP” and
“DOWN” are both inopera-
tive, but the Cowl Switch
does operate.
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. 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.
Trim Switch and Cowl Switch
are both inoperative.
1. One of the Trim Pump Motor wires is
open between the motor and the Relays.
2. Faulty trim pump motor.
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.
Trim system operates (motor
runs) without pressing the
switches.
1. The Trim or Cowl switch is shorted. 1. Replace

Mercury 40 Specifications

General

Horsepower	40 hp
Starting System	Electric
Steering	Remote
Fuel Induction System	EFI (Electronic Fuel Injection)
Shaft Length	20"
Full Throttle RPM Range	6000