The alternator “load dump” problem has become more serious with the increased use of electronic modules in today's “hi tech” automobile designs. An alternator rectifier device has been developed to contain the unwanted alternator voltage excursions that might occur should a connection become intermittent during a high charge rate cycle. These new avalanche rectifiers have been designed and constructed to withstand the hostile automotive environment. They are rated to operate as normal alternator rectifiers, and when required, will operate in a zener avalanche mode to clamp the alternator output voltage level to under 40 volts. The performance of these new rectifiers under load dump conditions is examined as well as the normal forward voltage drop versus current flow. The use of the avalanche rectifiers in the alternator design allows the automotive engineer to reduce the cost of protection for every individual electronics module in the vehicle.