The starter does not rotate when the ignition key is turned to the appropriate position
Low battery
Charge the battery.
Broken or bad wire connection «masses» (-). Low battery
Check wiring and contacts. Measure battery voltage. Charge it if necessary.
Insufficient current conduction due to weak or oxidized contacts
Clean the poles and battery terminals. Repair the connections between the battery, starter and «weight» (-).
No voltage at terminal 50 (traction relay)
Wire break. Faulty ignition switch and starter.
The starter turns too slowly and does not crank the engine
Low battery
Charge the battery.
Insufficient current conduction due to weak or oxidized contacts
Clean the poles and terminals of the battery, as well as the tips of the wires to the starter. Tighten the wire nuts on the starter terminals.
Carbon brushes not seated on commutator, stuck in guides, worn, broken, oily or dirty
Check carbon brushes and terminals, clean or replace. Check the carbon brush guides.
Insufficient distance between carbon brushes and commutator
Replace the carbon brushes and clean the carbon brush guides.
The collector is worn out, burned or dirty
Turn the collector or replace the anchor.
No voltage at terminal 50 (less than 10 V)
Check the ignition switch or traction relay.
Broken bearing
Check the bearing and replace if necessary.
Faulty traction relay
Replace the traction relay.
The starter engages and turns, but the engine does not turn or turns jerkily
Faulty gear train
Replace starter.
Starter gear dirty
Clean the gear.
Damaged flywheel ring gear
Replace flywheel.
Gear train does not disengage
Gear or screw splines dirty or damaged
Replace starter.
Faulty traction relay
Replace the traction relay.
Weak or broken return spring
Replace the traction relay.
The starter continues to rotate even after the ignition key is released
Traction relay stuck, won't turn off
Switch off the ignition immediately. Replace the traction relay.
Ignition switch won't turn off
Disconnect the battery immediately. Replace the ignition switch.