Test Lamp Method

With rectifier end shield and stator assembly separated, test rectifiers with a 12V battery and suitable test lamp. Connect test lamp to battery and measure rectifier continuity with probes of test lamp touching heat sink and rectifier top strap. Now reverse probes, if lamp lights with current flow in only one direction, rectifier is satisfactory. If lamp lights with probes either way, rectifier is shorted. If lamp does not light at all, rectifier is open. Test each rectifier and both assemblies in this manner.