Suzuki outboard motors 1988 2003 repair manual., Page 117Get this manual
IGNITION AND ELECTRICAL SYSTEMS 5-5 12 volt test light, connect the ground clip to good ground and probe wherever necessary with the pickThe test light will illuminate when voltage is detectedThis does not necessarily mean that 12 volts (or any particular amount of voltage) is present; it only means that some voltage is presentIt is advisable before using the test light to touch its ground clip and probe across the battery posts or terminals to make sure the light is operating properlyDo not use test light to probe electronic ignition, spark plug or coil wiresNever use pick-type test light to probe wiring on electronically controlled systems unless specifically instructed to do soAny wire insulation that is pierced by the test light probe should be taoed and sealed with silicone after testinaFig7 Jumper wires are simple, yet extremely valuable, pieces of test equipment
between set of test leads, fused jumper wire can be used for bypassing open circuitsUse amp fuse to provide protection against voltage spikesJumper wires are used primarily to locate open electrical circuits, on either the ground (-) side of the circuit or on the power (t)sideIf an electrical component fails to operate, connect the jumper wire between the component and good groundIf the component operates only with the jumper installed, the ground circuit is openIf the ground circuit is good, but the component does not operate, the circuit between the power feed and component may be openBy moving the jumper wire successively back from the component toward the power source, you can isolate the area of the circuit where the open is locatedWhen the component stops functioning, or the power is cut off, the open is in the segment of wire between the jumper and the point previously testedYou can sometimes connect the jumper wire directly from the battery to the "hot" terminal of the component, but first make sure the component uses 12 volts in operationSome electrical components, such as fuel injectors or sensors, are designed to operate on about to volts, and running 12 volts directly to these components will cause damageLike the jumper wire, the 12 volt test light is used to isolate opens in circuitsBut, whereas the jumper wire is used to bypass the open to operate the load, the 12 volt test light is used to locate the presence of voltage in circuitIf the test light illuminates, there is power up to that point in the circuit; if the test light does not illuminate, there is an open circuit (no power)Move the test light in successive steps back toward the power source until the light in the handle illuminatesThe open is between the probe and point which was previously probedThe self-powered test light is similar in design to the 12 volt test light, but contains 1.5 volt penlight battery in the handleIt is most often used in place of multimeter to check for open or short circuits when power is isolated from the circuit (continuity test)The battery in self-powered test light does not provide much currentA weak battery may not provide enough power to illuminate the test light even when complete circuit is made (especially if there is high resistance in the circuit)Always make sure that the test battery is strongTo check the battery, briefly touch the ground clip to the probe; if the light glows brightly, the battery is strong enough for testing A self-powered test light should not be used on any electronically controlled system or componentThe small amount of electricity transmitted by the test light is enough to damage many electronic marine componentsMULTIMETERS