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