Starter No Load Test. Buick Roadmaster 1996

For 1990-2009 cars

1. With the carbon pile (5) OFF, make the connections (Battery (1), Ammeter (2), voltmeter (3), starter motor (4), carbon pile (5)).
2. Close the switch, adjust the carbon pile in order to obtain 10 volts. Compare the RPM, current and voltage readings with the specifications. Refer to Starter Motor Usage .
3. Disconnect the leads only with the switch open.
4. Use the following information with the test results:

4.1. | Rated current draw and no-load speed indicates normal starter motor condition.

4.2. | Low free speed and high current draw indicates the following conditions:

• | Too much friction. This can be caused by tight, dirty or worn bearings, or bent armature shaft allowing armature to drag.

• | Shorted armature. This can be further checked with a growler after disassembly.

• | Grounded armature or fields. Check further after disassembly.

4.3. | Failure to operate with high current draw indicates the following conditions:

• | Direct ground in terminal or fields.

• | Frozen bearings (this can be determined by hand turning the armature).

4.4. | Failure to operate with no current draw indicates the following conditions:

• | Open field circuit. After disassembly inspect the internal connections and trace the circuit with a test lamp.

• | Open armature coils. Inspect the commutator for badly burned after disassembly.

• | Broken brush springs, worn brushes, high insulation between commutator bars or other causes which would prevent good contact between brushes and commutator.

4.5. | Low no-load speed and low current draw indicates the following conditions:

• | High internal resistance due to poor connections

• | Defective leads

• | Dirty commutator and causes listed above in step 4.4.

4.6. | High speed and high current draw usually indicate shorter fields. If shorted fields are suspected, replace the field coil. Check for shorted armature, using a growler.