Geotab HRN-CT26T1 Harness: Fitment, Install and Specs

What Is the HRN-CT26T1?

The HRN-CT26T1 is a custom Geotab harness that lets a GO9 device connect to a Tesla Model Y at a factory connector behind the lower center console. It is only 16.5 cm (6.5 in) long, and Geotab's listing states plainly that it requires a GO9.

Electric vehicles change the usual telematics routine. There is no engine bay full of familiar wiring, and the cabin is designed to look seamless, so installers need a connection point that is both correct and invisible once the trim is back. On the Model Y, Geotab's answer is this short harness, plugged in at the Tesla connector and hidden under the air vent assembly.

Schematic only: the harness plugs in at the Tesla connector and gives the GO9 its own branch.

Which Vehicles and Devices Does the HRN-CT26T1 Work With?

Geotab lists this harness for the Tesla Model Y and gives no year range on the listing, so we check the connector behind the console on each car. Other Tesla models use different harnesses: Geotab lists the HRN-CT20T11 for the 2019 and newer Model 3, and the HRN-CT06K1 kit for the redesigned Model 3 along with the Model S, Model X and 2022+ Plaid.

Device choice is fixed. Geotab requires a GO9 for the HRN-CT26T1, and its online guide is written around the GO9. The listing does not name a replaced part or any companion harness.

What Problem Does It Solve on the Job?

Fleets that add a Model Y, whether for sales staff, inspectors or an executive pool, want the same visibility they get from the rest of the fleet without anything showing in a cabin that drivers expect to stay clean. A dangling plug or a tracker stuck to the floor would get noticed, and probably removed.

The CT26T1 install answers both needs. The connection sits behind the lower center console, and the device lives on the underside of the air vent, out of sight but with a view of the sky through plastic and glass. Done properly, the only sign a tracker is fitted is the vehicle showing up in MyGeotab.

How Is the HRN-CT26T1 Installed?

Geotab's Model Y guide is mostly trim work, so patience and the right tools matter:

Park, slide both front seats fully forward for room, and have a panel tool, a T20 Torx driver, alcohol wipes and cable ties ready.
Release the lower center console panel by sliding the tool under its right side and twisting gently against the clips.
Remove the two T20 screws, pull the air vent panel outward and rest it on the console, then take out the panel beneath it.
Unplug the Tesla connector, plug in the HRN-CT26T1, make sure both connections are fully seated, and cable tie the connection, trimming the tail.
Plug in the GO9. Listen for six beeps and watch the red, blue and green LEDs blink. Lock the device to the harness with the black serialized tie.
Clean the underside of the air vent with an alcohol wipe, let it dry fully, apply double-sided tape, and press the GO9's antenna side onto it for 30 seconds.
Refit the panels in reverse order, pushing the vent wiring down so nothing is pinched, and refasten the T20 screws.
Start the car, wait for solid LEDs (ten beeps), and record the install in MyInstall with the asset name and VIN, then confirm it in MyGeotab.

Any added extension still has to keep the total under Geotab's 2 m (6.5 ft) ceiling, and two T-harnesses must never be linked.

Behind the lower console panel, the harness joins the Tesla connector and leads up to the GO9 on the underside of the air vent.

Spec	Detail
Part number	HRN-CT26T1
Vehicle	Tesla Model Y
Required device	GO9
Length	16.5 cm (6.5 in)
Connection point	Tesla connector behind the lower center console panel
Device mounting in guide	Double-sided tape on the underside of the air vent
Origin	China
Overall harness limit	2 m / 6.5 ft, all connected parts

What Should You Watch for When Fitting It?

Tesla trim is unforgiving, so use plastic tools and steady pressure rather than force. The tape only holds on a surface that is clean and completely dry, which is why the alcohol wipe and wait come first. When the vent panel goes back, push the GO9 cable down clear of the edges, because a pinched cable is the most likely cause of a callback. Keep the device's underside off metal and confirm both connections click before you close anything up.

Which Related Harnesses Should You Compare?

HRN-CT20T11: the Tesla Model 3 harness for 2019 and newer cars, also a GO9 part.
HRN-CT06K1: the kit for the redesigned Model 3 and 2022+ Model S and X Plaid.
HRN-CT06S1: the harness for late 2015 and newer Model S and X.

What Are Common Questions About the HRN-CT26T1?

Does the HRN-CT26T1 work with a GO10?

Geotab's listing says this harness requires a GO9 device, so that is the device we pair with it on a Model Y.

Where does the GO device end up on a Model Y?

Geotab's guide mounts it with double-sided tape on the underside of the air vent, antenna side against the tape, after cleaning that surface with an alcohol wipe and letting it dry.

How long does a Model Y install take with this harness?

Geotab does not publish a time. The job is mostly careful trim work: the lower center console panel, two T20 screws, the air vent panel and the panel beneath it, then reassembly in reverse.

Electric fleet vehicles get the same care from us as any work truck. API Signal supplies the HRN-CT26T1 and the GO9 and fits them on site at your yard or office lot, leaving the cabin as clean as we found it. Call 803-513-1009 for a time, or use Get a Quote to tell us about your Teslas.

Sources: Geotab Harness Identification and Application, Geotab HRN-CT26T1 Tesla Model Y guide, Geotab Tesla Model Y install document. GEOTAB is a registered trademark of Geotab Inc. API Signal is an independent installer and is not Geotab.

Every Geotab Harness →All 83 harnesses and accessories by part number. Get a Quote →The HRN-CT26T1 supplied and installed on one written quote.

Geotab HRN-CT26T1 Harness