24-11-2021, 07:36 PM
For brief testing joining the output and field terminals and connecting a 12v lamp to earth or just reading volts is fine but if run in this condition as can occur if the car battery connection comes adrift the dyn will eventually cook. Can drive thru a piece of hose or somesuch, or a loose socket to allow misalignment. 2500 rpm is quite high for a lathe.