Bench Testing: Brushes

Visually check brushes for burn spots or discoloration caused by arcing. Check brush length and replace if less than .15" (3.8 mm). New brush protrusion should be .39" (9.8 mm). Check brush continuity by touching one lead of ohmmeter to brush and other ohmmeter lead to brush terminal in brush holder. Check both brushes in this manner. If continuity exists in both brushes, brushes and holder are okay. If continuity does not exist in either position, replace brush holder and regulator as an assembly.