4l80e wiring harness | eBay www›Search›4l80e wiring harnessFind great deals on eBay for 4l80e wiring harness. Shop with confidence. Skip to main content. eBay Logo: 2 product ratings - 4L80E Transmission Wire Wiring Harness Internal 2004-up TOT 4L80 Automatic New. $49. FAST 'N FREE. Buy It Now. 4L80E 4L85E Sonnax 34998-01K Wire Harness Connector Bracket For Late Type Only See more like this. 4L60E to 4L80E Conversion - LT1 Swap The new speed sensor plug will hook to the INPUT speed sensor, located above the shifter shaft on the side of the 4L80E. That will complete the wiring changes at the transmission end. Now, you will need to go to the PCM connectors, and re-purpose the WHITE and TAN/BLACK wires for the input speed sensor.