The service manual will be your best friend when installing a tachometer on a Harley shovelhead. Harley-Davidson produced the shovelhead engine from 1966 to 1984. Some models, like the 1983 FXRT were factory stock with a hooded, dual speedometer and tachometer mounted on the handlebars. Many models were produced with a speedometer only. Its not unusual to find surviving shovelheads with missing speedometers, tachometers and turn signal lights, as some old-schoolers preferred to ride without them.
Instructions
- 1
Follow the service manual instructions to remove the seat and gas tank, only if necessary to install a tachometer on the specific year and model of the motorcycle. Use the hardware included with the tachometer kit to mount the tachometer to the desired location. Check the service manual instructions to properly disconnect the negative battery cable.
2Thread the three unterminated leads of the tachometer wire harness through the front forks and upper fork bracket. Run the terminated end of the wire harness back, along the frame toward the seat. Use zip-ties to secure the wires to the frame. Connect the black lead to the chassis ground.
3Use the service manual to locate the signal source for the year and model of the motorcycle. Connect the pink lead to the signal source. Study the fuses section and wiring diagram section of the service manual. Use the diagrams to find the power source for the model and year. Connect the orange and white lead to the power source.
4Connect the unterminated leads to the back of the tachometer. Connect the orange and white power lead to the positive post. Connect the black, ground lead to the G post. The pink lead connects to the S post. Use zip-ties to secure the tachometer wire harness to the motorcycle wire harness. Follow the service manual instructions to reinstall the seat and gas tank. Reconnect the negative battery cable.
5Refer to the operating recommendations for the recommended engine speed for the year and model. Turn the ignition switch on and start the motorcycle. The tachometer should indicate idle revolutions per minute and respond to throttle changes.