Mastering Geotab
★ Geotab Harnesses · Make-Specific and Custom Harnesses
The HRN-FUEL is a Geotab fuel gauge tap-in adapter harness that sits between a GO device and the HRN-GS16K22-A T-harness and picks up the analog signal from the vehicle's fuel level sender.
The HRN-FUEL is Geotab's fuel gauge tap-in adapter harness, which connects between the GO device and the HRN-GS16K22-A T-harness and adds one input wire for the analog fuel level signal from the vehicle's tank sender. It exists for vehicles whose engine computer does not report fuel level over the diagnostic port, so the GO device has to read the gauge signal directly.
In plain terms, it lets a fleet see tank level in MyGeotab on trucks that would otherwise show no fuel data at all. The harness does not touch the fuel system; it listens to the electrical signal that already feeds the dash gauge.
Geotab's identification table describes the HRN-FUEL as a fuel gauge tap-in adapter and lists the HRN-GS16K22-A, the universal OBD-II T-harness kit, as a requirement. Its length is 64 cm (25 in), and origin is China. In Geotab's Isuzu N-series guide, the GO device plugs into Connector 1 of the HRN-FUEL and Connector 1 of the HRN-GS16K22-A plugs into its Connector 2, so the adapter sits in the middle of the T-harness run.
Supported vehicles are set out in Geotab's fuel harness vehicle list. That list covers both this harness and the HRN-FUEL3W, and it currently names light and medium trucks from Isuzu, Hino, FUSO, Toyota, Daihatsu and Mitsubishi sold in Southeast Asian and Australian markets. Geotab notes that data availability can vary by build year and market. No North American market models appear on it today, so we check every vehicle against the list before quoting.
Fuel is often the biggest running cost a fleet controls, and theft or siphoning shows up first as a tank level that drops while the truck is parked. Many light trucks never put fuel level onto the diagnostic bus, which leaves managers relying on receipts. The HRN-FUEL gives the GO device a direct read of the gauge, so overnight drops, short fills and refuel events become visible.
It also fills gaps in mixed fleets, where newer vehicles report fuel through engine data and older or simpler trucks do not. With the adapter in place, both groups appear in the same fuel reports.
Geotab limits its vehicle guides for this harness to authorized installers, and soldering is involved. Using the Isuzu N-series guide as the model:
Geotab caps any harness chain at 2 m (6.5 ft) and forbids plugging one T-harness into another.
| Spec | Detail |
|---|---|
| Part number | HRN-FUEL |
| Made in | China |
| Function | Fuel gauge tap-in adapter harness |
| Requires | HRN-GS16K22-A universal T-harness kit |
| Position | Between the GO device and the HRN-GS16K22-A |
| Length | 64 cm (25 in) |
| Signal lead | Green ANALOG FUEL wire, soldered to the sender signal |
| Supported vehicles | Per Geotab's fuel harness vehicle list |
Panel layouts, cluster pinouts and sender wire colors differ between makes, and Geotab says its Isuzu guide does not transfer to other trucks, so the right vehicle guide comes first. Strip the sender wire well back from the connector so the factory plug can still be serviced. A cold or crimped joint on a low-voltage analog signal gives jumpy readings, so solder it and tape it. Count the adapter's 64 cm into the total harness length before adding any extension.
No. Geotab lists the HRN-GS16K22-A universal T-harness as a requirement. For vehicles wired by the three-wire method instead, Geotab offers the HRN-FUEL3W.
Yes. Geotab's vehicle guides have the green analog fuel wire soldered to the fuel sender signal wire, then insulated, rather than crimped or tapped with a clip.
Geotab publishes a fuel harness vehicle list, and at the time of writing it is made up of trucks and pickups sold in Southeast Asian and Australian markets. If a vehicle is not listed, Geotab takes model support requests, and we can file one with the details for the customer.
Fuel monitoring done right starts with checking the truck against Geotab's list, and we handle that before any part ships. API Signal supplies Geotab harnesses and GO devices and fits them on site at the customer's yard, drawing on 35 years of twelve-volt work. Give us a call at 803-513-1009 or open Get a Quote.
Sources: Geotab harness identification, HRN-FUEL; Geotab fuel harness vehicle list; Geotab fuel harness guide, Isuzu N-series. GEOTAB is a registered trademark of Geotab Inc. API Signal is an independent installer and is not Geotab.
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