Mastering Geotab
★ Geotab Harnesses · Heavy-Duty Deutsch Harnesses
The HRN-DS09S4 is a 100 cm (39 in) straight harness that connects a GO device to a 9-pin Deutsch diagnostic port and lets it sit well away from the driver. It replaces the HRN-C9HD and suits trucks where the port can be dedicated to telematics.
The HRN-DS09S4 is a straight 9-pin harness, 100 cm (39 in) long, made for North American heavy-duty vehicles with a Deutsch diagnostic connector. Its job, in Geotab's words, is relocation: getting the GO device out of the driver's way rather than leaving it hanging from a port beside the steering column.
The word "straight" is the key to choosing it. A straight harness has one vehicle connector and one device connector and nothing in between, so the truck's 9-pin port is taken by the harness for as long as it is installed. That is a different design from a T-harness, which hands the factory connector back for other tools. In exchange, the straight design gives you a full metre of reach in a single, simple run. It replaces the older HRN-C9HD.
It fits North American heavy-duty trucks and buses that carry the round 9-pin Deutsch diagnostic port. Geotab's cheat sheet places that port on heavy trucks from about 2000 onward.
On the device side, this is a harness from the generation before the GO10. Geotab's GO10 material says that device cannot connect directly to harnesses designed for earlier GO devices, and the 9-pin choice in its GO10 section is the HRN-XGS09K2. If a fleet is mixing GO9 and GO10 units, we sort the harnesses per truck before the visit.
Geotab's vehicle notes add one bus-specific requirement. On 2017 IC PB105 school buses, this straight harness must be modified before use: the wires in positions C and J trade places so yellow moves to J and blue to C, and green moves from D to H while purple moves to D. The same notes say devices older than version 7 are not compatible with that bus.
When the 9-pin port sits low beside the steering column, a plugged-in device rests right where a knee goes, and a driver climbing in and out of a tall cab can catch it every shift. Moving the device a metre away, behind a side panel or up under the dash structure, ends that problem.
The straight harness also suits fleets that do not use the port for anything else on a daily basis. If the shop plugs in diagnostic software only occasionally, unplugging the harness for that visit is a small price for a single, clean connection with no extra leg to tie off.
Where even 100 cm is not quite enough, Geotab allows a straight harness to be joined to a T-harness or another straight harness where its guide indicates that pairing, as long as the total stays inside 2 m (6.5 ft). We check the guide for the exact combination before building it.
Park the truck, set the brake and switch off the ignition; Geotab forbids fitting harnesses or devices on a moving or running vehicle. Inspect the truck's 9-pin port for bent or recessed pins and clean debris out of it. Then plan the route from the port to the device location so the cable will not cross a pedal, the steering column or a sharp panel edge.
Seat the 9-pin Deutsch connector on the port and turn its coupling until it is fully engaged. Lay the cable along an existing loom, connect the GO device at the other end and orient it so its antenna side faces up. Fasten the device and the cable with cable ties at regular intervals, since a heavy cable left loose will sag into the footwell over time.
Keep the whole connected harness length at 2 m (6.5 ft) or less, and never connect two T-harnesses to each other if an extra T is added for some reason. Start the engine, allow the device to initialize and show its LEDs, then complete the MyInstall check and watch for the truck's engine data to arrive in MyGeotab.
| Spec | Detail |
|---|---|
| Part number | HRN-DS09S4 |
| Type | Straight 9-pin heavy-duty Deutsch harness |
| Length | 100 cm (39 in) |
| Replaces | HRN-C9HD |
| Vehicle connector | 9-pin Deutsch diagnostic port, North American heavy-duty |
| Known modification | 2017 IC PB105 school bus: swap C/J and move D to H per Geotab notes |
| Max connected cable length | 2 m (6.5 ft) |
| Country of origin | China |
Confirm the port is a 9-pin before ordering; older trucks may have a 6-pin, which takes a different harness. Turn the Deutsch coupling all the way home, because a partly engaged connector can drop data under vibration without falling off. If the vehicle is a 2017 IC PB105, do the documented pin moves before connecting, or skip the work by fitting the HRN-GS09K2 T-harness kit, which Geotab says needs no change on that bus. Keep a note in the vehicle file that the port is occupied, so the shop knows to unplug the harness for diagnostics.
No. It is a straight harness, so it takes over the 9-pin port with no pass-through for other tools.
Geotab lists it at 100 cm, or 39 inches, from the Deutsch connector to the device connector.
Yes. Geotab's notes say it must be re-pinned for 2017 IC PB105 school buses, with C and J swapped, green moved from D to H, and purple moved to D.
API Signal stocks the HRN-DS09S4 with the GO devices and fits it on site at your yard, including any documented re-pinning, so the truck goes back to work the same day. Dial 803-513-1009, or start with Get a Quote.
Sources: Geotab Harness Identification and Application, Geotab vehicle-specific installation notes, Geotab harness cheat sheet, Geotab guide to telematics harnesses. GEOTAB is a registered trademark of Geotab Inc. API Signal is an independent installer and is not Geotab.
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