Basic Electrical Diagnostics | Resistance Testing

The multi-meter showed a resistance of 0.1 Ohm between each commutator bar. It showed the armature is good.

But the power supply set at 7amps and 3Volts showed between most bars had a 0.8V drop, but some had 1.4V drop. Meaning some windings have higher resistance under load. This test proved that the armature is weak.