Starter No Load Test

NOTE: Never operate the starter motor for more than 30 seconds at a time. Allow it to cool at least two minutes before cranking again. Excessive cranking can cause overheating, which will cause serious damage to the starter motor.

Starter No Load Test:

Make connections as shown. Close the switch and compare the RPM, current, and the voltage readings with the values shown in the Starter Motor Usage table. Starter Motor Usage

If the starter does not meet these values replace the starter. The following conditions indicate possible causes of starter problems.
^ Rated current draw and no-load speed indicates normal condition of the starter motor.
^ Low free speed and high current draw indicates the following.
- Too much friction - tight, dirty or worn bushings, bent armature shaft allowing armature to drag
- Shorted armature
- Grounded armature or fields
^ Failure to operate with high current draw indicates the following.
- A direct ground in the terminal or fields
- Frozen bearings
^ Failure to operate with low or no current draw indicates the following:
- Open solenoid windings
- Open field circuit
- Open armature coils
- Broken brush springs, worn brushes, high insulation between the commutator bars or other causes which would prevent good contact between the brushes and commutator.
^ Low no-load speed and low current draw indicates the following.
- High internal resistance due to poor connections, defective leads or a dirty commutator
- Open solenoid windings
- Open field circuit
- Open armature coils
- Broken brush springs, worn brushes, high insulation between the commutator bars or other causes which would prevent good contact between the brushes and commutator
^ High free speed and high current draw usually indicate shorted fields.