Yamaha Outboard Tachometer Wiring Diagram: How to Wire it
An outboard tachometer is essential for monitoring the revolutions per minute (RPM) of a vehicle or machine. They are used in cars and boats and read more than 6000 RPM. However, Yamaha Outboard Tachometer wiring installation is not always easy, and diagrams are vital as a visual aid.
Then how to wire it? A basic installation involves matching the wire colors from the tachometer to the engine. The yellow tachometer wire connects to the ignition source as the power and the blue wire goes to the headlight switch. Thus, the green signal wire goes to the negative side of the ignition coil.
The article covers more about Yamaha outboard tachometer wiring diagrams and guides on how to do it.
Yamaha Outboard Tachometer Wiring Diagram
While Yamaha tachometers are direct plug-and-play installations, the many colors are sometimes confusing. Also, if your boat uses a different engine, the colors on the connectors might not match the wires on the outboard tachometer.
The following diagram contains the wiring diagram of the Yamaha outboard tachometer.
How to install an Outboard Tachometer
The first Tachometer is said to have been made by Dietrich Uhilhorn in the early 19th century and was used to measure speed. However, with time the models have improved, and now they have multiple functions and can display more information about a vehicle.
Yamaha has different models, including the 6Y8 for the analog models and 6YC information station for the digital. So the installation can sometimes be confusing since there can be up to 10 wires in a tachometer.
While Yamaha uses green for their sending unit, most brands use gray, which can cause uncertainty. The worst part is that Suzuki uses yellow as the sending unit and that is often mistaken for Yamaha’s ignition power.
Here, the following table contains the most basic colors for the Yamaha outboard tachometer. We have also tagged their corresponding functions for your perusal.
Wire Color | Function |
Red | Battery 12 Volts positive |
Yellow | Ignition switch 12 Volts positive |
Dark Green | Tachometer (sending unit) |
Black | Battery 12 Volts negative (Ground) |
Blue | Backlight |
Before installing the outboard tachometer, decide the ideal position to place it in your dashboard. Some Yamaha tachometers have short wires and must be near the mounting point. Thus, the gauge should be at least 20 inches from a compass to prevent interference.
In addition to that, learn about your engine model and the right colors to match your tachometer wires before you start. For a Yamaha engine, the colors should straightforwardly match the harness colors.
The use of modern harnesses allows the installation to be a simple plug-and-play. Connecting yellow and blue together will cause the backlight to illuminate when the ignition key is on.
For older models with no harness, you must clip and connect wires manually. You’ll require insulated wires that are not lighter than 18 AWG approved for marine use. Follow the steps below to install your outboard Yamaha tachometer.
Step 1: Use a screwdriver to turn the selector switch to match the number of poles in your alternator for the correct RPM calibration. If you don’t know the number, consult the outboard tachometer application chart.
Step 2: To the tach stud marked “BAT,” connect a yellow wire, then connect it to the ignition switch.
Step 3: For the tach stud marked “SIG”, connect to the negative side of the alternator.
Step 4: Connect the tach stud marked “GND” with a wire, then attach it to the boat’s electrical ground.
Step 5: Then connect the light stud to the positive side of the vehicle’s instrument lighting circuit.
Remember, you should use dielectric grease in all connectors to avoid corrosion leading to a failing gauge. Besides, you can always consult the user manual bought with the gauges for more information.
Is It a Must to Calibrate a Yamaha Tachometer After Installation?
Tachometers are fairly accurate as their accuracy is ± 0.05% with a tiny margin of error. However, calibration is necessary, especially for the first time since you might mismatch the number of poles during installation.
Accordingly, the calibration is done to match the frequency with the engine RPM using a digital multimeter. Connect the digital multimeter negative lead in the earth wire, which is black in Yamaha engines. Then connect the positive lead to the green multimeter wire and set the reading to hertz to monitor frequency.
Now start the engine and observe the idle speed; then convert the results to RPM by multiplying by 60. Divide the answer by the number of poles, divided by 2 because each pole is negative or positive.
Afterward, compare the RPM you will get using the math with the tachometer’s RPM. If they mismatch, you should adjust the poles using the selector.
Are Yamaha Outboard Tachometers Worth It?
While there are many tachometer manufacturers in the world, several qualities make Yamaha unique. The ability to monitor several things is one of the qualities and the various models. Below are the Yamaha qualities that make their gauges unique.
- The tachometers are visible using polarized sunglasses, which most boat owners use to see through the glare
- Thus, the troll mode in Yamaha is smooth, going as low as 500 RPM
- You can monitor various engine functions, including temperature, battery, alarm, and trim among others
- Yamaha tachometers are also waterproof and affordable compared to other brands
If you were wondering whether or not to invest in a Yamaha outboard tachometer, you are well answered now. If the above qualities are enough proof that you will get value for your money, why not go for it?
Key Takeaways
A tachometer proves to be very useful in gauging an engine’s performance and ensuring it runs at a smooth RPM. While it’s hard to install one, the Yamaha outboard tachometer wiring diagram can provide a visual aid to help you through.
On top of that, you can always hire a professional to fix the gauge for you or consult the user manual.
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