1. Insufficiently tightened or oxidized terminals on the terminals of the battery (see «Battery - Maintenance»).
2. The battery is low or defective (see «Battery - Maintenance»).
3. Faulty starter circuit (see «Starter»).
4. Faulty starter drive parts (see «Starter - repair»).
5. Defective starter relay (see «Starter - repair»).
6. Faulty motor (anchor, windings, brush assembly) starter (see «Starter - repair»).
7. Faulty switch (lock) ignition (see «Switch (lock) ignition - check»).
8. Damaged or worn flywheel ring gear (see «Flywheel - removal and installation»).