Starter motors used on Holden vehicles are generally very durable, but after many years of service the internal components such as brushes, bearings and electrical windings can begin to wear. When a starter motor begins to crank slowly, fail to engage or draw excessive current it may need to be tested to confirm whether the fault lies within the motor itself or elsewhere in the starting system. Bench testing allows the starter to be checked outside the vehicle where its electrical performance and mechanical operation can be observed directly. The procedures described here apply to the common Bosch, Lucas and Delco Remy starter motors used on many classic Holden engines.
Safety note
Starter motors draw extremely high electrical current. Always secure the starter motor firmly before testing and ensure battery cables cannot accidentally short against metal surfaces. If testing is carried out while the starter is still installed in the vehicle, ensure the vehicle is safely supported using axle stands and never rely solely on a jack.
Preliminary inspection
Before performing electrical tests, several visual checks should be carried out.
• Inspect the starter drive pinion for worn or damaged teeth
• Check that the drive mechanism moves freely
• Inspect electrical terminals for corrosion or loose connections
• Ensure the starter motor casing and mounting surfaces are clean
• Check that the solenoid linkage moves freely
Mechanical faults discovered during this inspection should be corrected before further testing.
Lock test
The lock test measures the starter motor’s torque output and current draw while the armature is prevented from rotating. This test determines whether the motor can produce sufficient torque to crank an engine.
Typical lock test values for many Holden starters are:
• Current draw: approximately 290 to 430 amps depending on model
• Voltage: approximately 4.2 to 7.0 volts
• Minimum torque output: approximately 15 lb-ft for many six cylinder starters
If current draw is significantly higher than specified, the starter motor may have internal electrical faults or excessive friction. If current draw is unusually low, worn brushes or poor electrical contact may be preventing proper current flow.
No-load test
The no-load test measures the speed and current draw of the starter motor when it is allowed to spin freely without load.
Typical no-load test values include:
• Current draw: approximately 40 to 87 amps depending on starter type
• Voltage: approximately 10.6 to 12 volts
• Speed: approximately 5000 to 10700 rpm depending on model
Low speed during the no-load test usually indicates internal friction, worn bearings or electrical resistance within the armature windings.
Solenoid testing
The starter solenoid performs two functions: it engages the starter drive with the flywheel and connects battery power to the motor. If the solenoid fails to operate correctly the starter motor may not crank the engine.
Typical solenoid test values include:
• Pull-in voltage: approximately 7.5 volts maximum
• Hold-in voltage: approximately 1.0 volt maximum
A solenoid that fails to engage properly may have worn contacts, damaged wiring or a weak internal coil.
Diagnosing starter motor faults
Bench testing can help identify a range of common starter motor problems.
• Worn brushes reducing electrical contact
• Burnt or damaged armature windings
• Excessive friction in bearings or bushings
• Faulty solenoid contacts
• Internal electrical resistance within the motor
Correct diagnosis helps determine whether the starter motor should be repaired, rebuilt or replaced.
While this guide helps identify common engine problems, the Holden workshop manuals available from Car Manuals Direct include the original specifications, adjustment settings and repair procedures used by Holden mechanics when these vehicles were new.