Remove the insulation from the wires in the harness. Only remove enough insulation to solder in the new diode.Install the new diode in the harness, making sure current flow is correct. If necessary, refer to the appropriate wiring diagram for current flow.Solder the connection together using rosin core type solder only. Do not use acid core solder.Tape the diode to the harness using electrical tape. Make sure the diode is completely sealed from the elements.Re-connect the battery and test affected systems.