Brush Assembly Test

Using a test light, touch probes to each brush. Bulb should not light. See Fig 1.

Fig 1: Checking Brush Assembly with a Test Light Bulb should not light when both brushes are touched.
Connect test leads to field terminal and its corresponding brush. Bulb must light, even when brush is moved in its holder. Test negative terminal and corresponding brush in similar manner. Bulb must again light even if brush is moved in its holder.