A tachometer is a gauge used to measure revolutions per minute and is often referred to as rpm. The revolutions per minute indicate the rate of rotation of the engine crankshaft while in operation. This gauge supplies vital information to the operator to help ensure the engine is always running in a safe range. Teleflex Marine sells many different boating gauges including tachometers that can be installed in your boat in a few hours.
Examine the rear of the tachometer. Find the four wiring terminals and notice their positions and labels. These terminals are for ignition, ground, signal and illumination. Look at the wiring harness included with the gauge and notice the four wires that connect to the rear terminals.
Strip about half an inch of the insulation from the end of the red wire. Loosen the small nut from the terminal marked "IGN" on the back of the tachometer with a nut driver or small open end wrench. Wrap the end of the wire around the post and tighten it. Connect the other end to output side of the ignition switch. Probe the terminal of the switch with a voltage tester to make sure you connect to the correct side. Crimp a quick connect terminal on the end of the wire or use a wire tap connector to supply the power.
Strip half an inch of insulation from the black wire. Connect this wire to the "GRD" terminal at the back of the tachometer the same way you did in Step 2. Connect the other end to a ground source. Locate the grounding block secured to the rear of the dashboard or run the wire to the negative terminal on the battery.
Open the engine compartment and locate the distributor at the rear center of the engine. It will have all of the spark plug wires connected to it. Find the tachometer terminal on the side of the plastic case. Find the green wire with the matching tachometer terminal on the end of it. Press the connector onto the terminal and run the wire back to the gauge. Terminate this end to the connection point marked "SEND."
Locate an unused switch on the dash panel or install a new one if you want the gauge to illuminate. Connect one side of the switch to a 12 volt power source. Connect the white wire between the other side of the switch and the wiring post on the rear of the tachometer marked "LT."
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