Baja Designs' 640115 is a universal on/off power harness that runs a single LED light from the battery through a dash-mounted switch. Its one plug is a weather-resistant three-pin connector, and the manufacturer lists it for OnX6+ bars from 10 to 20 inches, S8 bars from 10 to 30 inches, and a single XL Sport or XL Pro auxiliary light. Because the light-side plug seals against moisture, the kit suits trail rigs that see mud, water crossings, and dust.
A purpose-built harness costs more than improvised wiring, but it removes the guesswork. Owners on user forums report that factory upfitter wiring is often too thin to carry a full light bar reliably, so a dedicated harness is the safer route. An on/off switch comes in the box, so you do not need to source a separate toggle. The matched connector also means you are not hunting for an adapter to get your bar to talk to a generic kit.
Bar length is the main fitment check. Owners searching for an OnX6+ 20-inch bar harness, an S8 10-inch wiring kit, or an XL Pro auxiliary light harness should confirm their bar falls inside the stated range. Mounting hardware is not included, so plan on your own brackets and wire management for the run from the battery to the light.
The manufacturer rates this harness for one 10–20 inch OnX6+ bar or one 10–30 inch S8 bar. For a two-light setup, the manufacturer's 640119 OnX6/XL Hi-Power harness is listed for two lights with a mode switch, at 355 watts.
The manufacturer states the 640115 will not work with OnX6+ bars 30 inches and longer, or S8 bars 40 inches and longer. The manufacturer directs 30–50 inch OnX6+ bars to its 640119 harness instead.
The manufacturer lists an on/off switch as included. Its listing for this SKU does not mention a relay or fuse, so confirm with the manufacturer before wiring.
The manufacturer describes installation as simple, since the harness has positive and negative battery leads and a single plug at the light end. The manufacturer's install sheet for its sibling 64-0119 harness, which uses the same style of switch and light plug, calls for a 10mm or 1/2-inch socket for the battery terminals and 1/2-inch and 3/4-inch drill bits for the dash switch holes. Disconnect the battery ground before wiring. Before you pull the switch terminals, photograph the switch wire orientation so you can reconnect it correctly. Route the cable through the firewall and dash, and tie all wiring away from hot, sharp, or moving parts. Confirm the 640115 specifics against the manufacturer's sheet, since that sheet covers a different SKU.
