Posted 10.23.26 in Tips & Instructions
Your XKmax bar is out of the box, and now it needs power. The typical LED light bar wiring diagram online shows a plain white bar run through a relay and a fuse. XKGLOW's XKmax Dual-Mode LED Light Bar adds a controller with sensor wires. The bar has two modes, Light Bar and DRL, and only one runs at a time.
This guide turns XKGLOW's instruction sheet into a wire-by-wire table and numbered steps. There is one sheet per bar length, 7 to 50 inches, and all six print the same wiring page.
What the XKmax Light Bar Wiring Diagram Shows
The wiring page covers two pieces: the leads on the bar, and the harness that feeds them.
On the bar, a red lead goes to 12V+ and a black lead goes to ground. If you came looking for a two-wire diagram, those are your two. Next to the power cable sits a port marked XKmax output plug, and a cable of sensor wires runs off the back of the bar.
The harness connects the light bar to the vehicle's battery. Its drawing starts with red and black ring terminals and an inline fuse on the red lead. From there it runs through a power relay to a plug for the bar, a green sensor lead and a switch labeled DRL Mode and Light Bar.
The product page lists a manual switch as one of three ways to toggle modes, along with the XKmax app and a sensor.
The Diagram, Wire by Wire
Read each row against the drawing on your own sheet.
| Wire or part | Color or label | Connects to | What it does |
|---|---|---|---|
| Battery positive lead | Red, ring terminal | 12V+ at the battery | Feeds the harness through the inline fuse |
| Battery ground lead | Black, ring terminal | Ground | Grounds the harness |
| Inline fuse | Drawn on the red lead | Between the ring terminal and the relay | Fuses the positive feed |
| Power relay | Labeled Power Relay | Every other harness lead | Ties the battery leads to the bar plug, sensor lead and switch |
| Bar plug | Arrow labeled Light Bar | The light bar | Joins the harness to the bar |
| Bar power leads | Red marked TO 12V+, black marked TO GROUND | 12V+ and ground | The bar's own power and ground |
| Green sensor lead | Green, on the harness | The bar's yellow sensor wire | Links the harness to the yellow wire |
| Yellow sensor wire | Yellow, on the bar's sensor cable | The harness's green lead; XKGLOW also recommends the high beams | Preset to run Light Bar mode |
| Two more sensor wires | Same sensor cable | Turn signals or a reverse light | Optional; settings on the app's Configuration page |
| Mode switch | Labeled DRL Mode and Light Bar | The harness, through a plug-in connector | Manual switch marked for the bar's two modes |
| XKmax output plug | Port on the back of the bar | The next unit in a series (optional) | Series connection, per its label |
Whatever light bar wiring kit you end up running, XKGLOW sets two minimums: 12-gauge wire and "a switch capable of your light bar's power rating." The spec table puts input voltage at 11 to 14 volts.
How to Wire a Light Bar: XKGLOW's Steps
XKGLOW's order is test, wire, then pair. Here it is with the harness, mounting and app pages folded in.
- Bench-test it first. Before the bar goes anywhere, connect red to 12V+, black to ground, and the green wire to the yellow sensor wire. Scan the QR code on the sheet to download the XKmax app, connect to the bar's controller, and cycle the bar between DRL and Light Bar mode. If you spot a defect, XKGLOW asks you to contact them immediately.
- Mount the bar. Fix an angle bracket to each end with the supplied socket allen head bolts. Choosing the spot is covered in our guide to the best place to mount a truck light bar.
- Make the permanent connections. The final install repeats the same three joins, this time through the harness. Run the red ring terminal to 12V+ at the battery, with the inline fuse in that lead. Take the black ring terminal to ground, and stick to 12-gauge wire or heavier.
- Connect the bar and the sensor lead. Connect the harness's bar plug to the light bar, then join its green lead to the bar's yellow sensor wire. The mode switch joins the harness through its own plug.
- Read the high-beam recommendation. The app section of the sheet adds a suggestion for that yellow wire: tap it into the high beams. Light Bar mode then comes on whenever your high beams do.
- Add the optional sensor wires. The other two sensor wires can connect to your turn signals or a reverse light. Both are optional.
- Pair the app and set the defaults. Open the XKmax app and pair it to the bar's rear-mounted controller. Out of the box, every power-up starts in DRL mode. To start in Light Bar mode instead, or to change the DRL color, open the Default Mode setting on the app's Configuration page. Sensor-wire settings live on the same page.
Running a Second XKmax Bar
The XKmax output plug on the back of the bar carries the label "use to connect to series" and is marked optional.
Extra bars come from the product page in all six lengths. Each add-on arrives without a controller of its own and draws on the first bar's XKmax controller.
Install Time, Pro Help and Warranty
XKGLOW lists the install at 1 to 2 hours. Its instruction sheet recommends a licensed professional for the job, and the bar's five-year limited warranty excludes damage from improper installation. Register the bar to activate that coverage.
Prefer an expert on the job? Find one through XKGLOW's dealer locator.
Road use is a separate question. The sheet asks you to check local and state laws for proper use, and our light bar road rules guide quotes the codes of three states.
Building out the rest of the truck? Start with our guide to choosing truck LED lights. Build yours today.
Frequently Asked Questions
How to wire an LED light bar properly?
Test it before you mount it, then wire it exactly as the instruction sheet draws. For the XKmax Dual-Mode bar, run red to 12V+ through the inline fuse and black to ground. Join the harness's green lead to the yellow sensor wire, and use 12-gauge wire or heavier.
Do I need a relay for an LED light bar?
XKGLOW's diagram for the XKmax Dual-Mode bar includes one. Its harness runs the red battery lead through an inline fuse to a power relay. The relay also connects to the bar plug, the green sensor lead and the mode switch. Follow that diagram from the battery to the bar.
Which wire is positive on a LED light?
Red, on the XKmax Dual-Mode bar. The bar's red lead is marked TO 12V+ and its black lead TO GROUND. The harness keeps the same colors at the battery end, with its red ring terminal on 12V+ and the black one on ground.
How to wire LED with 3 wires?
On the XKmax Dual-Mode bar, the three extra wires are sensor wires on a cable off the back of the bar. The yellow one ships set to Light Bar mode and joins the harness's green lead. The other two are optional and can go to turn signals or a reverse light.
