Brush Assembly Test
Connect an ohmmeter (or test lamp) between field terminal and bracket. Resistance should be high (infinite) or test bulb should not light. If resistance is low or test bulb lights, brush assembly is shorted and must be replaced. To test for continuity, connect ohmmeter to field terminal and insulated brush, resistance should be zero. Move brush and brush lead wire, resistance should not vary. Connect ohmmeter to bracket and grounded brush, resistance reading should be zero.