A starter motor is a key electrical device for starting equipment or vehicles. A starter motor starts a stationary engine by converting electrical energy from the battery into mechanical energy and overcoming the engine torque. Only after the engine is started can the vehicle or equipment enter normal operation. Therefore, its quality will have a direct impact on the starting and performance of the equipment.

Common issues often encountered with the starter motor on the equipment include instances where it fails to engage, struggles with insufficient power, continues to rotate after starting, experiences freewheeling, and produces abnormal noises during startup. The following combined with the automotive starting system circuit, to analyze the basic methods of fault diagnosis.

 

1. Starter does not turn

When the starter doesn't turn over when the key is in the starter gear, it could be either a faulty battery or a faulty starter.

Possible causes of battery failure: 1. insufficient battery capacity or loss of power; 2. loose, oxidized or corroded terminals; 3. poor hitch.

Treatment: 1. replace or charge the battery; 2. tighten or clean the terminals and then tighten; 3. remove dirt or corrosion and tighten.

 

Possible causes of starter motor failure: 1. loose oxidation or corrosion of the terminal; 2. electromagnetic switch contacts ablation, the main contacts and moving contacts can not be closed; 3. armature winding or excitation winding burned short-circuit or disconnection; 4. lead damage, poor lap; 5. brush can not be sliding freely up and down in the brush frame, brush spring pressure is weak; 6. commutator surface burns, its contact with the brush is poor.

Treatment: 1. tighten or clean the terminal after tightening; 2. repair or replace the electromagnetic switch point or coil; 3. repair or replace the armature winding or excitation winding; 4. repair; 5. replace or repair the brushes, brush springs; 6. replace or repair the commutator, brushes.

 

2. Starter motor starts weakly

A starter that turns over slowly and weakly should be troubleshooted not only for the starter but also for the battery.

Possible causes of battery failure: insufficient battery capacity or loss of power; loose, oxidized or corroded terminals; poor lap iron.

Treatment: replace the battery or charging; tight weeks or clean the terminals after tightening; remove dirt or corrosion and tighten.

 

Possible causes of starter motor failure: 1. loose, oxidized or corroded terminals; 2. electromagnetic switch contact erosion or poor contact; 3. wire welding; 4. commutator surface burns, poor contact with brushes; 5. stator-rotor friction between each other; 6. excitation windings or armature windings local short circuit. Make the starter motor power down; 7. one-way clutch slippage; 8. lubricating oil due to cold and make the viscosity too large; 9. bushings wear.

Treatment: 1. tighten or clean the terminals after tightening; 2. overhaul electromagnetic switch; 3. re-welding; grinding with fine sand, so that the brush and commutator surface friction; 4. overhaul; overhaul or replace the excitation winding or armature winding; replacement of the one-way clutch; 5. warming and drying the engine; 6. replacement of the shaft lining.

 

3 The starter motor continues to rotate after the engine is started

After the engine has started, if the starter does not stop turning when the electrical ignition switch is released from the starting gear, then the engine should be turned off by immediately disconnecting the ignition switch.

If the starter motor stops even after the engine is turned off, check to see if the starter motor is installed correctly. For example, whether the tooth side clearance is too small, whether the freewheel is jammed, and whether the starter drive gear and ring bite and do not return.

 

Possible causes of failure: 1. Stuck freewheel and starter gear reset spring is too weak or broken; 2. drive gear and ring bite; improper installation of starter, tooth side clearance is too small; 3. solenoid switch contact sintered or core reset spring spring is not enough; starter system starter relay contact sintered; 4. ignition switch short circuit; The contact of the starter relay of the starter system is sintered; 5. the ignition switch is short-circuited.

Treatment: 1. overhaul or replace the freewheel; 2. check whether the battery is undercharged; 3. reinstall and overhaul the starter; 4. overhaul or replace the relevant parts of the electromagnetic switch; 5. overhaul or replace the starter relay; 6. overhaul or replace the ignition switch.

 

After the engine is turned off, if the starter is still running at high speed, the main power switch should be cut off immediately, otherwise the starter will be damaged due to constant running and affect other diesel engine parts. this kind of failure is generally caused by the electromagnetic switch contact sintering or the core reset spring spring force is not enough; for the starter system with starter relay, the failure may also be caused by starter relay contact sintering or ignition switch short circuit. For starter systems with a starter relay, the failure may also be caused by a sintered starter relay contact or a shorted ignition switch.

 

4 Starter motor idling

Starter motor idling, or idling at a lower speed, or high speed idling, but can not start the engine. There are two kinds of this kind of failure:

The first kind: the starter drive pinion and flywheel ring engagement, or the occurrence of the top teeth and can not be engaged. The fault is mainly in the starter one-way clutch slippage or wheel tooth damage.

The second type: the starter drive pinion can not engage with the flywheel ring and idling, the fault is mainly in the starter control part.

 

Possible causes: 1. one-way clutch slippage; 2. drive pinion and flywheel gear ring top teeth or tooth ring is broken; 3. engine flywheel gear ring missing teeth; 4. toggle fork wheel gear ring missing teeth; 5. fork connection disengagement; 6. electromagnetic switch stroke is too short.

Treatment: 1. overhaul or replace the one-way clutch; 2. overhaul or replace the engine flywheel ring; 3. replace the engine flywheel ring; 4. overhaul or replace the electromagnetic switch; 5. adjust the electromagnetic switch stroke.

 

 

5 starter motor abnormal noise

The cause of the starter motor abnormal noise is relatively complex, for this kind of failure should be carefully observed, comprehensive analysis to make the maintenance program.

1.Possible causes: 1. starter drive pinion or engine flywheel ring damage; 2. starter installation loosening; 3. electromagnetic switch main contact premature connection; 4. armature shaft liner wear; 5. stator bore and rotor outer circle friction; 6 stator pole loose; armature shaft bending; 7. deceleration device is damaged.

Treatment: 1. overhaul the starter drive pinion; 2. adjust and tighten the starter; 3. adjust the main contact of electromagnetic switch; 4. replace or repair the armature shaft. 5. Replace or repair the bushings of the armature shaft; 6. replace or repair the stator and rotor; 7. overhaul the magnetic poles in the stator; 8. replace or repair the armature shaft; 9. replace or repair the deceleration device.