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. jeep wrangler tj engine harness | eBay Find great deals on eBay for jeep wrangler tj engine harness. Shop with confidence. Skip to main content. eBay Logo: 2004 Jeep Wrangler TJ ENGINE WIRE HARNESS No A/C 2 5 Spd 4 Cyl 56047222AC See more like this. 2004 Jeep Wrangler Rubicon TJ 4 manual Engine Harness 56044453AC 04.