HomeBloghow to make a tach adapter

how to make a tach adapter

Creating a tachometer (tach) adapter typically involves modifying or building an electronic circuit to convert the signal from your vehicle’s ignition system into a format that can be read by an aftermarket tachometer. The exact design of the adapter may vary depending on your vehicle’s ignition system and the specifications of your tachometer. Here’s a simplified guide on how to make a basic tachometer adapter:

Materials You’ll Need:

  1. Components for the Tachometer Adapter Circuit:
    • Integrated Circuit (IC): You will need a microcontroller or an IC like a 555 timer or a microcontroller (e.g., Arduino) depending on your design.
    • Resistors: To set up voltage dividers or pull-updown resistors as needed by your circuit.
    • Capacitors: For filtering and timing purposes.
    • Diodes: If required for signal protection or rectification.
    • Wires: To connect components.
    • Breadboard or PCB (Printed Circuit Board): To build your circuit.
  2. Soldering Iron and Solder (if using a PCB): If you’re building a PCB-based adapter.
  3. Power Source: Depending on your design, you may need a power supply or batteries.


Please note that this is a simplified explanation, and creating a tachometer adapter can be a complex task that requires electrical engineering knowledge. Consider consulting with a professional or an electronics expert if you are not experienced in electronics.

  1. Design Your Circuit:
    • Research the specific requirements of your vehicle’s ignition system and the tachometer you want to connect. Different vehicles and tachometers may require different circuit designs.
    • Determine the type of signal your vehicle’s ignition system produces. It may be a pulse signal, a sine wave, or another waveform.
  2. Select an IC or Microcontroller:
    • Choose an appropriate IC or microcontroller that can read and process the signal from the ignition system and convert it into a format compatible with your tachometer.
    • If you’re using a microcontroller like Arduino, you’ll need to write code to handle the signal conversion.
  3. Assemble Your Circuit:
    • Connect the components on a breadboard or PCB according to your circuit design.
    • Ensure that the power supply voltage matches the requirements of your chosen IC or microcontroller.
    • Pay close attention to wiring and connections, as accuracy and reliability are crucial for tachometer readings.
  4. Calibrate and Test:
    • Calibrate your tachometer adapter to ensure that it accurately reads the engine’s RPM.
    • Connect the adapter to your vehicle’s ignition system and the tachometer.
    • Start the vehicle and observe the tachometer’s readings to verify that they match the engine’s RPM.
  5. Secure and Encase (Optional):
    • Once you’ve confirmed that your tachometer adapter is working correctly, you can secure the components and encase the circuit in a suitable housing for protection.

Creating a tachometer adapter is a complex electrical project, and the design will vary depending on your specific vehicle and tachometer. If you’re not experienced in electronics, it’s advisable to seek assistance from someone with expertise in electrical engineering or automotive electronics to ensure a safe and accurate installation.