The regulator limits voltage as to not damage the battery and the electrical components. The rectifier converts AC voltage to DC voltage, which is used to keep the battery charged and to operate the electrical system. Symptoms of a failed or failing regulator/rectifier include the battery not properly charging, hard starting, and blown out light bulbs. Discount Starter & Alternator sells brand new replacement regulator/rectifier units for commercial-grade farm tractors and agricultural equipment. We cover the major manufacturers including Case, Bosch, Ford, International, New Holland, Allis Chalmers, and more. Browse our extensive online inventory and shop with confidence at Discount Starter & Alternator.