ESA-01 GM Transmission to Electronic Speedometer Converter

Upgrade your classic GM transmission to work with modern electronic speedometers using the ESA-01 Transmission to Electronic Speedometer Converter.

The ESA-01 replaces the factory mechanical speedometer cable drive and generates a reliable electronic speed signal suitable for SAAS electronic speedometers and many other aftermarket gauge systems that accept a 12V square wave input.

Perfect for Holden restorations, street machines, hot rods, custom builds and electronic dash conversions, the ESA-01 provides a simple and reliable solution for converting older GM transmissions to electronic speedometer operation without modifying the transmission.

✅ Features

✅ Converts mechanical speedometer cable output to an electronic speed signal

✅ Compatible with SAAS electronic speedometers

✅ Suitable for many aftermarket speedometers accepting a 12V square wave input

✅ No transmission modifications required

✅ Direct bolt-in installation

✅ Full installation instructions included

✅ Speedometer calibration compensates for diff ratio, gearbox gearing and tyre size

✅ CNC-machined aluminium housing

✅ Waterproof connector with locking clip

✅ Includes 2.7m double-insulated wiring loom

✅ Ideal for Holden Commodore, muscle car and custom dash conversions

🔌 How It Works

The ESA-01 installs directly into the factory speedometer cable output on compatible GM transmissions and generates a 12V square wave signal (16 pulses per revolution) for your electronic speedometer.

Simply connect:

✅ Ignition-switched 12V power

✅ Ground

✅ Speed signal wire

Your electronic speedometer can then be calibrated to accurately display vehicle speed regardless of differential ratio, gearbox ratio or wheel/tyre size.

🔧 Transmission Compatibility

Standard ESA-01 Option

Suitable for compatible GM transmissions with a 7/8"-18 speedometer cable connection and 0.104" (2.64 mm) square drive, including:

✅ Powerglide

✅ TH350

✅ TH400

✅ Other compatible GM transmissions using a 7/8"-18 speedometer cable output

Square Drive Pin Size: 0.104" (2.64 mm)

🔧 ESA-02 Adapter Option (+$155)

Some transmissions do not have the correct speedometer cable connection required for the ESA-01 to install directly.

For these applications, the ESA-02 Cable Adapter is required and allows the ESA-01 converter to be used with:

✅ Holden Trimatic

✅ M20 4-Speed Manual

✅ M21 4-Speed Manual

The ESA-02 adapter connects between the transmission and the ESA-01 converter, providing the correct interface for these transmissions.

 

⭐ Premium Construction

Built for long-term reliability in automotive environments:

✅ Aluminium CNC-machined body

✅ Corrosion-resistant finish

✅ Waterproof electrical connection

✅ Secure locking connector

✅ Quality wiring loom included

📋 Specifications

✅ Mounting Thread: 7/8"-18 Female

✅ Square Drive Pin Size: 0.104" (2.64 mm)

✅ Connector Type: 3-Pin Waterproof Connector

✅ Output Signal: 12V Square Wave

✅ Pulse Rate: 16 Pulses Per Revolution

✅ Power Requirement: Fused 12V Ignition Supply

✅ Housing Material: Aluminium

✅ Cable Length: 2.7 Metres

✅ Wiring: 3-Core Double Insulated Cable

📦 Available Options

Option 1 — ESA-01 Converter Only

✅ ESA-01 Transmission to Electronic Speedometer Converter

Suitable for Powerglide, TH350, TH400 and other compatible GM transmissions with a 7/8"-18 speedometer cable output and 0.104" (2.64 mm) square drive.

Option 2 — ESA-01 Converter + ESA-02 Adapter (+$155)

✅ ESA-01 Transmission to Electronic Speedometer Converter

✅ ESA-02 Cable Adapter

Required for Holden Trimatic, M20 and M21 transmissions.

⚠️ Please Check Fitment Before Ordering

Transmission configurations can vary depending on the vehicle, transmission and previous modifications.

Before ordering, please confirm your transmission has the required connection and 0.104" (2.64 mm) square drive.

If you're unsure whether the ESA-01 will suit your transmission, please contact us before ordering and we'll be happy to help confirm compatibility.