1974 Johnson 135 HP Outboard Motors Service manual, Page 94Get this manual
DESCRIPTION
The complete electrical system is made up of the ignition system, the starler system, the alternator charging system, and the storage batteryAl so included are the instrument and cable group, See Figure 7-1 at end oC Section 8This section will cover the starter system and the charging system, and battery maintenance
TROUBLESHOOTING THE elECTRICAL SYSTEM
Trouble in the electrical system often is first evidenced by failure of the starter to operate, and may be caused by failure of anyone or more of the components covered in this sectionIf an ammeter does not indicate charging with the engine rwming, or if the battery fails to retain enough charge to conSistently start the engine, the first things to check are he condition of the battery, polarity of the battery, and electrical connections throughout the circuitA large percentage of electrical circuit as well as component failures are caused by loose or dirty el ectrical wiring connections, especially in the starter circuitBattery maintenance and charging system troubleshooting are covered belowSt arter system troubleshooting is included in the Trouble Check Chart in Section 2