Mercury Mariner 200, 225 Optimax Outboards Service Manual, 90-855348, Page 305Get this manual
Electrical System Troubleshooting GENERAL CHECKS
2Make certain all connections are tight and corrosion free3Check that plug-in connectors are fully engaged4Make certain battery is fully chargedRefer to the preceding four wiring diagrams for connection points when troubleshooting the electrical systems (Connection points are specified by number
Before troubleshooting the Power Trim electrical system, check the following: 1Check for disconnected wires
Troubleshooting the "Down Circuit"
Connect Voltmeter red lead to Point and black lead to groundDepress the "Down" trim buttonI
Battery Voltage Indicated: Connect Voltmeter red lead to Point 3No Voltage Indicated: Connect Voltmeter red lead to Point and black lead to groundDepress "Down" trim buttonIf battery voltage is indicated, wire is open between Points and 1Battery Voltage Indicated: .Connect Voltmeter red lead to Point 2.Depress "Down" trim buttonNo Voltage Indicated: