1989 Ford F 350 Diesel Wiring Diagrams . Finally bit the bullet and purchased a new coil, ecu, distributor, plug wires, distributor cap, rotor and (icm from earlier). 7.3l wiring schematic printable, very handy. 1989 Ford F250 Wiring Diagram 1989 Ford E350 Wiring Diagram Data from glossybeautyyy.blogspot.com Handy wiring diagram that shows a paper trail of how the electrical system works for the 7.3l powerstroke engines, all trucks, excursions, vans. Got all new components put in and it started. 1989 f250 ford fuel switch relay.