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 size.

🔧 Transmission Compatibility

Standard ESA-01 Option

Suitable for GM transmissions with a 7/8"-18 speedometer cable connection, including:

✅ Powerglide

✅ TH350

✅ TH400

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

🔧 ESA-02 Adapter Option (+$140)

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

✅ 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

Suitable for Powerglide, TH350, TH400 and other GM transmissions with a 7/8"-18 speedometer cable output.

Option 2

✅ ESA-01 Converter + ESA-02 Adapter (+$140)

Required for Holden Trimatic, M20 and M21 transmissions.