Alternator Anti-Feed Back Diode Harness Plug 10SI 12SI 15SI 27SI - 2pk.Designed for vehicle charging systems as a protective anti-feed back diode harness connector assembly.Prevents reverse current flow and protects the alternator and vehicle electrical system from damage.Professional electrical connector assembly with secure terminal connections.Direct replacement plug that integrates seamlessly with existing vehicle alternator wiring.Ensures reliable alternator operation by maintaining proper current flow direction in the charging system.