Mastering Geotab
★ Geotab Harnesses · Special Order, European and Accessories
The HRN-BD16S5 is a Geotab special-order harness for ALDL installs on gas and OBD vehicles such as GM and Ford, and on Freightliners with a gateway. It connects through the vehicle's original connector instead of an EZT bracket.
The HRN-BD16S5 is a Geotab harness for ALDL installations, used on gas and OBD vehicles such as GM and Ford models and on Freightliner trucks equipped with a gateway. ALDL, short for assembly line diagnostic link, is the old GM name for the diagnostic connector, and installers still use the term. Geotab's key line about this part is that it uses the vehicle's OEM connector rather than an EZT bracket.
Put simply, it is a way to mate the GO device into the factory connection where a standard bracket-style install is not the right fit. Geotab files it under its special-order harnesses, meaning it is ordered for a known application rather than kept on every service van. Its published length is 130.5 cm (51.5 in), which is long enough to move the device well away from the driver's knees.
The part also carries a regulatory note. Geotab's harness guide lists the HRN-BD16S5 as one of its continuously connected aftermarket parts that has been granted an Executive Order by the California Air Resources Board, making it compliant for use in that market.
Geotab names three groups: gas vehicles with an ALDL connection, OBD vehicles such as GM and Ford, and Freightliners that use a gateway. It does not publish a year or model list, so the deciding factor is what is actually behind the dash of the vehicle in front of us. That is why we look at the connector and the existing setup before ordering.
Geotab's harness guide lists the type as a T-harness, and the identification document limits the total connected length to 2 m (6.5 ft). At 130.5 cm, that leaves about 69.5 cm for anything else in the run. The entry does not name a specific GO model. When a newer GO10 is going into a vehicle that needs an older specialty harness, we check whether Geotab's bridge adapter is required before the job is booked.
Most light-duty installs are routine: a universal T-harness, a mounting adapter at the port and a tidy device behind the panel. Some vehicles do not cooperate. A bracket-style install may not seat properly, may stress the port, or may not suit a Freightliner where the data passes through a gateway. A harness that mates with the factory connector keeps the connection solid and leaves the vehicle's own hardware intact.
The long cable also matters on vans and trucks where the port sits low and exposed. Moving the device up and behind trim keeps it away from boots, kneeboards and drivers who unplug things out of curiosity.
For fleets running in California, the CARB Executive Order is a practical selling point, because it means the harness is cleared for use there as an aftermarket part.
Geotab does not post a step-by-step guide for this harness in its identification document. Our sequence follows Geotab's general harness and device rules:
| Spec | Detail |
|---|---|
| Part number | HRN-BD16S5 |
| Application | ALDL installs on gas and OBD vehicles (e.g. GM, Ford) and Freightliners with gateway |
| Connection | Uses OEM connector instead of EZT bracket |
| Type | Listed as a T-harness in Geotab's harness guide |
| Length | 130.5 cm / 51.5 in |
| Max connected cable length | 2 m / 6.5 ft |
| California | Granted a CARB Executive Order, compliant for the California market |
| Ordering | Special order |
| Country of origin | China |
At 130.5 cm on its own, there is little room left under the 2 m ceiling, so extensions are rarely an option. Do not combine it with another T-harness under any circumstances; Geotab warns that two T-harnesses together can corrupt data and upset the engine computer. On a Freightliner, confirm the gateway arrangement first rather than assuming any 16-pin truck qualifies. If a dash warning, stall or loss of power appears after fitting, shut the engine off and remove the device, and our technicians trace the cause.
ALDL stands for assembly line diagnostic link, an older GM name that installers still use for the diagnostic connector. Geotab lists this harness for ALDL installations on gas and OBD vehicles such as GM and Ford, plus Freightliners with a gateway.
Geotab's harness guide lists the HRN-BD16S5 among its aftermarket parts that have been granted an Executive Order by the California Air Resources Board, which makes it compliant for that market.
Geotab groups it with harnesses that are ordered for specific applications, where price and lead time are set per order. We confirm the vehicle actually needs it before ordering so a truck is not held up waiting for the wrong part.
API Signal supplies and installs Geotab harnesses and devices on site at the customer's yard, backed by 35 years in twelve-volt work. Call 803-513-1009 or use Get a Quote to have us check your vehicles.
Sources: Geotab Harness Identification and Application, Geotab harness guide. GEOTAB is a registered trademark of Geotab Inc. API Signal is an independent installer and is not Geotab.
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