Mercury 15 EFI FourStroke, Service Manual

Page: 102 / 406

Starting System
Starting System Description
The battery supplies energy to spin the starter motor. When the start button or key switch is activated, the starter solenoid is
energized and completes the starting circuit between the battery and starter.
The neutral start switch opens the start circuit when the shift control lever is not in neutral. This prevents accidental starting
when the engine is in gear.
NOTICE
Engaging the starter motor while the engine is operating can damage the starter motor or flywheel. Do not engage the starter
motor continually for longer than 15 seconds. Do not engage the starter motor when the engine is operating.
Starting System Components
The starting system consists of the following components.
•
Battery
• Starter solenoid
• Neutral safety switch
• Starter motor
• Start button or key switch
Starter Solenoid Test
1. Disconnect all wires from the solenoid.
2. Connect an ohmmeter (R × 1 scale) between terminals 1 and 2.
3. Connect a 12‑volt power supply between terminals 3 and 4.
• The solenoid should click, and the meter should read 0 ohms (full continuity).
• If the meter does not read 0 ohms (full continuity), replace the solenoid.
65142
1
2
3 4
DMT 2004 Digital Multimeter 91‑892647A01
Troubleshooting the Starting Circuit
Before beginning the starting circuit troubleshooting flowchart, first check for the following conditions:
•
Ensure that the battery is fully charged.
• Ensure that the control lever is in the neutral position.
• Ensure that the lanyard clip is on the E‑stop switch.
• Check terminals for corrosion and loose connections.
• Check that the battery cables are connected to the correct polarity terminals: red (+), black (–)
• Check cables and wiring for frayed and worn insulation.
• Check the in‑line fuse.
Charging and Starting Systems
90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 2B-11