Jeep Wiring Harness | eBay A Jeep engine wiring harness will have connections and cables made specifically to fit your vehicle, whether that's a Jeep Wrangler or Grand Cherokee; you cannot use a wiring harness from another vehicle with your engine. Turn to reliable sellers on eBay to find the correct wiring harness for your Jeep. Jeep Wiring Harnesses | Quadratec Painless wiring offers both universal kits and Jeep model specific kits so you can get your entire Jeep wired. When you need to add an accessory, parts like the Quadratec 12 volt power adapter make it easy to get power without cutting into any factory wiring, or creating a rats nest of wires attached to your Jeep Jeep Chassis Wire Harness - Engine & Transmission Wiring The purpose of a Jeep YJ wiring harness is to deliver electrical and other information to places your rig needs it. Many of the Jeep's systems have their own wiring harnesses. For example, your rig has a Jeep transmission wiring harness and an engine wire harness assembly. Unfortunately, over time, wiring harnesses can wear out.