If ever there was a "King" wiring system, it's this one for the "King" itself the D21! Custom built all through the system and set up for a high amp Delco "SI" series Alternator. (included) Complete kit takes care of the "King" of Tractors. Our Polyethelene crosslinked Marine wire housed in our cotton woven tar/fiberloom with shrink tube connectors makes this one bullet proof wiring system for the big D21. New Delphi flat terminals and connectors do away with the old Molex pin style connectors that Mother Nature played havoc with. A tube of Dielectric grease comes in the kit as well to make those connections weathertite! Puts the original system to shame! One gauge heavier wire gets rid of low voltage issues throughout the wiring system. Our 10 "SI" Alternator bolts right up and takes the place of the old Delco "DN" series Alternator and external Voltage Regulator! Upgrade to a B&B wiring system built for the "King" of AC Tractors!