Geotab HRN-RW03K4-A Harness

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What Is the HRN-RW03K4-A?

The HRN-RW03K4-A is a three-wire harness kit for the GO RUGGED, supplied with a fuse kit, that powers the device from loose leads when a machine has no diagnostic connector to plug into. Geotab lists it at 100 cm (39 in), and it supersedes the earlier HRN-RW03S4.

Geotab places this kit among its non-ECM harnesses, the options for assets where the device is not connecting to an engine computer. That is a common situation on older or smaller equipment, and on many machines where the only practical connection points are the battery feed, a ground and an ignition-switched circuit.

Which Vehicles and Devices Does the HRN-RW03K4-A Work With?

The device is the GO RUGGED. Geotab's GO9 RUGGED documentation lists the three-wire kit as the option with no diagnostic connector, and the device itself runs on 12 V or 24 V systems. On the vehicle side, Geotab's harness assessment cheat sheet sends these assets to non-ECM harnesses: equipment with engines under 25 hp, equipment with no diagnostic port, and yellow-iron machines without a port. It also states that Komatsu equipment with no 12-pin port requires the HRN-RW03K4-A.

The cheat sheet's dividing line between on-highway and off-road is the VIN: an asset with a valid 17-character VIN is treated as on-highway, and anything else follows the equipment table, where Geotab says the GO RUGGED is mandatory. Geotab lists a maximum connected cable length of 2 m (6.5 ft) and China as country of origin.

What Problem Does It Solve on the Job?

Generators, compressors, light towers, small loaders and older machines often have nothing for a telematics device to plug into. Fleet managers still want to know where those assets are, when they run and how many hours they log. A three-wire GO RUGGED install gives location, ignition-based run time and the device's own sensing without any diagnostic connector.

It is also the upgrade path Geotab points to for older installs. Geotab strongly recommends that 12 V and 24 V customers moving from a GO8 or older device to a GO9 or newer replace the cable harness with an approved version, and this kit replaces the older RW03S4.

How Is the HRN-RW03K4-A Installed?

Geotab requires professional installation for the GO RUGGED, by a Certified Geotab Installer or someone with equivalent knowledge. Geotab publishes a dedicated installation guide for this kit; our technicians work from it alongside these GO RUGGED requirements:

1. Record the GO RUGGED serial number and add it to the MyGeotab database before installing, so the first data lands in the right place.
2. With the machine parked and secure, confirm it runs with no dash warning lights and that lights and signals work.
3. Identify a constant power source, a sound ground and a true ignition source on the machine; Geotab's three-wire kits are documented around constant power, ground and an ignition feed that is live only with the key on.
4. Connect the leads, fitting the supplied fuse on the power side as the kit instructions direct.
5. Mount the GO RUGGED, which Geotab permits outside the cab, and fasten the device and harness with cable ties away from moving parts and controls.
6. Start the machine, check that the device beeps six times and powers on, watch the ignition, GPS and cellular LEDs, and confirm it reports in MyGeotab before closing out in MyInstall.

Geotab's general harness rule caps total harness length at 2 m (6.5 ft). This kit has no diagnostic plug, so T-harness chaining does not arise, but any extension added must stay inside that limit.

Which Related Harnesses Should You Compare?

• HRN-RW04K4: for machines with a ground-side battery disconnect, an oil pressure switch or a negative ignition output, where a plain three-wire hookup will not read ignition correctly.
• HRN-RW03K5: a pulse harness for non-ECM engines that report neither ignition nor RPM.
• HRN-RW08K1: the eight-wire GO RUGGED kit that adds data lines for an unsupported OEM connector.
• HRN-CW03K3: the three-wire kit for GO9-family devices on on-highway vehicles with no port.

What Are Common Questions About the HRN-RW03K4-A?

What does the HRN-RW03K4-A replace?

It supersedes the older HRN-RW03S4 in Geotab's listing. Customers moving 12 V or 24 V equipment from a GO8 or older to a GO9 or newer are strongly advised by Geotab to change to an approved harness such as this one.

Which machines need a three-wire GO RUGGED harness?

Geotab's cheat sheet points off-road equipment with no diagnostic port, or with an engine under 25 hp, to its non-ECM harnesses, and names the RW03K4 family for yellow-iron machines and Komatsu units without a port.

Is a fuse included with the HRN-RW03K4-A?

Yes. Geotab lists the kit as the harness plus a fuse kit, so the power connection is protected without sourcing parts separately.

API Signal supplies and installs GO RUGGED devices and three-wire kits on site at the customer's yard or job site staging area. Call 803-513-1009 or use Get a Quote to get your equipment tracked.

Sources: Geotab Harness Identification and Application; Geotab Harness Assessment Cheat Sheet; Geotab GO9 RUGGED; Geotab 3-Wire Harness Kit document. GEOTAB is a registered trademark of Geotab Inc. API Signal is an independent installer and is not Geotab.