Mercury Electric Outboards 222 Thruster Service Manual, Page 44Get this manual
ELECTRICAL COMPONENT TESTING General 1For removal and installation of individual electrical components, refer to appropriate procedure as outlined in this Service Manual (see "Index") 2If an electrical component tests faulty when tested without disconnecting the wires, disconnect wires from component and retest to make sure that problem is not in the wiring3Check for open and short circuits, as follows: aWhen checking electrical wiring, flex and twist the wiring (particularly the rubber handle harness onRC" models) to detect intermittent contact in the wIringhVisually inspect wiring for cuts, chafing, disconnected terminals, pinched wires, etccOn "RC" models, check each harness wire for possible short circuit to control cabledOpen circuit (no continuity thru wire); wire may be cut or broken inside of the insulationeShort circuit (contact between or more wires); broken insulation andor pinched wires making connectionElectrically isolate and check each wire individually to all other harness wiresContinuity between wires indicates short circuitfShort to ground (contact between any wire and ground); broken insulation andor pinched wire contacting control housing, motor housing, foot pedal C'RC"), control cable C'RC"), etc