farmall wiring harness | eBay Find great deals on eBay for farmall wiring harness. Shop with confidence. Skip to main content. eBay Logo: Shop by category. Farmall H 300 350 M 400 450 12V Single Wire Alternator Conversion Wiring Harness. Brand New. $26. Buy It Now +$4 shipping. 17 Sold 17 Sold. Farmall 400 Diesel Complete Wire Harness - The Brillman #B3024-103, Complete Wire Harness For Farmall 400 Diesel Tractors Original Design With Generator & Voltage Regulator Truly braided to look exactly like the original & made with our Cotton Braid over PVC wire with all terminals soldered, sealed & the wire groups truly braided. Additionally, all wires come numbered & with a installation guide!