Mercury 20 EFI FourStroke Service Manual

Step Test Procedure Test Result
Step 1: Check for
battery voltage at
point 1.
1. Connect voltmeter red lead to point 1
and black lead to ground.
2.
Press the down tilt button.
Battery voltage measured:
• Go to step 2.
No battery voltage measured:
• Go to step 3.
Step 2: Check for
battery voltage at
point 3.
Connect voltmeter red lead to point 3 and
black lead to ground.
Battery voltage measured:
• Go to step 5.
No battery voltage measured:
• There is an open circuit between point 3 and positive
(+) battery terminal.
• Check for loose or corroded connections.
• Check wires for open.
Step 3: Check for
battery voltage at
point 4.
1. Connect voltmeter red lead to point 4
and black lead to ground.
2. Press the down tilt button.
Battery voltage measured:
• Wire is open between points 4 and 1.
No battery voltage measured:
• Go to step 4.
Step 4: Check for
battery voltage at
point 5.
Connect voltmeter red lead to point 5 and
black lead to ground.
Battery voltage measured:
• Tilt switch is faulty.
No battery voltage measured:
• Check for loose or corroded wire at point 5.
• Open circuit in wire supplying current to point 5.
Step 5: Check for
battery voltage at
point 2.
1. Connect voltmeter red lead to point 2
and black lead to ground.
2. Press the down tilt button.
Battery voltage measured:
• Go to step 6.
No battery voltage measured:
• Relay is defective.
Step 6: Check up
relay.
Test up relay. Refer to Power Tilt Relay
Test, preceding.
Relay is good:
• Pump motor wiring is defective.
• Pump motor is defective.
Relay is faulty:
• Replace relay.
Troubleshooting the Up Circuit
NOTE: Refer to the preceding wiring diagrams for test points when troubleshooting the electrical systems. Test points are
specified by number.
Step Test Procedure Test Result
Step 1: Check for
battery voltage at
point 8.
1. Connect voltmeter red lead to point 8
and black lead to ground.
2. Press the up tilt button.
Battery voltage measured:
• Go to step 2.
No battery voltage measured:
• Go to step 3.
Step 2: Check for
battery voltage at
point 9.
Connect voltmeter red lead to point 9 and
black lead to ground.
Battery voltage measured:
• Go to step 5.
No battery voltage measured:
• There is an open circuit between point 9 and positive (+)
battery terminal.
• Check for loose or corroded connections.
• Check wires for open.
Step 3: Check for
battery voltage at
point 7.
1. Connect voltmeter red lead to point 7
and black lead to ground.
2.
Press the up tilt button.
Battery voltage measured:
• Wire is open between points 7 and 8.
No battery voltage measured:
• Go to step 4.
Power Tilt
Page 5B-16 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017

Mercury 20 EFI FourStroke Specifications

General

Brand	Mercury
Model	20 EFI FourStroke
Category	Engine
Language	English