AXM-100 High Voltage Tach Adapter

Many classic tachometers—especially those from the 1970s and earlier—were designed to trigger off the negative terminal of the ignition coil, relying on a high-voltage spike rather than a modern 0–12V square wave. If your vintage tachometer refuses to respond to an ECU’s tach output (such as from MS3Pro, MicroSquirt, or MSPNP Gen 2), the AXM-100 is your solution.

This adapter steps up low-voltage square wave signals to mimic the original coil-induced voltage spike, ensuring compatibility with older analog tachs.

Applications

The AXM-100 is ideal for vehicles including:

• American muscle cars (1960s–1970s)

• European classics (up to the 1970s)

• Japanese cars (1980s and some 1990s, especially Toyota)

Key Features

• Converts 0–12V or 0–5V tach output signals to high-voltage coil-equivalent spikes

• Works with MS3Pro, MS3Pro PNP, MicroSquirt, MSPNP Gen 2, and more

• Amphenol AT connector (Deutsch DT compatible) for robust motorsport wiring

• Conformal-coated PCB protects against moisture and harsh environments

• Not compatible with current-triggered tachometers (those connected to the coil’s positive terminal)

Installation Notes

• Designed for dry environments—do not submerge

• Wire inline with your ECU’s tach output and the original tachometer input

• Mount securely with adequate strain relief on wiring