Starter No-Load Test
- Connect ammeter in series with a 12-volt battery and BAT terminal on solenoid. Connect a voltmeter between solenoid terminal "M" and ground. Connect a carbon pile rheostat across battery. See Fig 1 .
- Connect a switch between solenoid BAT and "S" terminals. Close switch and compare RPM, amperage, and voltage readings with specifications. See STARTER SPECIFICATIONS
.CAUTION: DO NOT apply more than 12 volts to starter, as excessive voltage may cause armature to throw windings because of excessive speed.
- If current draw and RPM meet specification, starter motor is okay. If test indicates low free speed and high current draw, unit may have tight, dirty or worn bearings, shorted armature, grounded armature, or grounded fields.
- Failure to operate, along with high current draw, indicates a direct ground in terminal fields or frozen bearings. Failure to operate, along with no current draw, indicates an open field circuit, open armature coils, or broken brush springs.
- Low no-load RPM and low current draw indicates high internal resistance due to poor connections, defective leads, or dirty commutator. High free speed and high current draw indicates shorted fields.