No-Load Test

No Load Test:

Make connection as shown. Close the switch and compare the RPM, current, and voltage readings with values shown in ''Starter Specifications". Use the test results as follows:
1. Rated current draw and no-load speed indicates normal condition of the starter motor.
2. Low free speed and high current draw indicates:
- Too much friction - tight, dirty, or worn bushings, bent armature shaft allowing armature to drag.
- Shorted armature. This can be further checked on a growler after disassembly.
- Grounded armature or fields. Check further after 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 low or no current draw indicates:
- Open solenoid windings. Check solenoid resistance values (See "Cleaning, Inspection and Testing"). Cleaning, Inspection and Testing
- Open field circuit. This can be checked after disassembly by inspecting internal connections and tracing circuit with a 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-load speed and low current draw indicates:
- High internal resistance due to poor connections, defective leads, dirty commutator and causes listed under step Number 4 above.
6. High free speed and high current draw usually indicate shorted fields. If shorted fields are suspected, replace the field and frame assembly. Also check for shorted armature, using a growler.