No Load Test (Typical)

Starter Motor No Load Test:

Remove the starter motor from the engine. The motor should be given a no-load test before disassembly.

Make connection as shown in image. Close the switch and compare RPM, current, and voltage readings with "Specifications."
Make disconnection's only with the switch open. Use the test results as follows:
1. Rated current draw and no-load speed indicates normal starter motor condition.
2. Low free speed and high current draw indicates:
^ Too much friction. This can be caused by tight, dirty, or worn bushings, or a bent armature shaft allowing the armature to drag.
^ A shortened armature. This can be further checked on a growler after disassembly.
^ A grounded armature or fields. check further alter disassembly.
3. Failure to operate with high current draw indicates:
^ A direct ground in the terminal or fields.
^ "Frozen" bearings.
4. Failure to operate with no current draw indicates:
^ An open field circuit. This can be checked after disassembly by inspecting internal connections and tracing circuit with a self-powered test lamp.
^ Open armature coils. Inspect the commutator for badly burned bars after disassembly.
^ Broken brush springs, worn brushes, high insulation between the commutator bars or other causes which would prevent good contact between the brushes and commutator.
5. Low no-lead speed and low current draw indicates:
^ High internal resistance due to poor connections, defective leads, dirty commutator and causes listed above under Number 4.
6. High free speed and high current draw usually indicate shorted fields. When shorted fields are suspected, replace the frame and field assembly. Also check for shortened armature, using a growler.