How is it possible that an alternator turning at cranking speed can put out in excess of its rated power? The one on my race car runs off of the pinion shaft, and does nothing at all until the car is going about 45 MPH. Is it possible to shut off the alternator while cranking the engine?

Lynn E. Hanover

There are also automatically resetting circuit breakers available. Another solution would be a slow blowing fuse. These are more tolerant of surging currents. I would not want to be flying around with a 100 amp fuse for alternator protection unless the wires were sized to handle that load for a sustained period. But that is just my opinion.

Jim Maher