- a) Battery is defective;
- b) The quality of the electrical connection between the ignition switch, the starter traction relay, the battery and the starter motor is broken;
- c) Faulty traction relay;
- d) There is mechanical or electrical damage to the starter motor.
2. To check the battery, turn on the headlights. If after a few seconds the brightness of the headlights decreases, then the battery is discharged and needs to be recharged or replaced (see Section Checking the status and charging the battery). If the brightness of the headlights does not change, turn the ignition key - if this time the brightness of the glow drops, then the current reaches the electric motor and the starter itself is faulty. If the brightness of the headlights still remains unchanged and at the same time the click of the operation of the traction relay is not heard, then there is a malfunction of the relay itself or its electrical circuit. If the starter turns too slowly, and the battery level is normal, then either the starter itself is malfunctioning, or the resistance in the circuit is excessively high.
3. If there is a suspicion of a malfunction in the electrical circuit, disconnect all wires from the battery (including earth bar on the body). Also disconnect the electrical wiring from the starter / traction relay and the ground bus of the power unit. Carefully clean the contact terminals, then restore the original wire connection and, using a voltmeter or test lamp, make sure that there is full voltage at the terminal connecting the positive battery wire to the traction relay. Make sure the grounding is correct. Lubricate the terminal connections of the battery terminals with acid-free petroleum jelly to prevent corrosion - remember that corrosion is the most common cause of poor electrical connections.
4. If the condition of the battery and all electrical connections is found to be good, check the circuit itself. Disconnect a wire from the knife plug of the traction relay of a starter. Connect a voltmeter between the end of the wire and a well grounded point (e.g. negative battery terminal) and check for presence in the power circuit with the ignition key turned to the START position. If power is supplied properly, then the circuit is in order. If there is no voltage, check the condition of the circuit.
5. Checking the contact connections of the traction relay can be done by connecting a voltmeter or test lamp between the power terminal on the side of the relay facing the starter and ground. With the ignition key turned to the START position, voltage should be present. Otherwise, the traction relay must be replaced.
6. If the condition of the electrical circuit and the traction relay is found to be in good order, the cause of the failure may lie in the failure of the starter electric motor and further verification is beyond the qualifications of the average amateur mechanic. Before asking for help, do a little marketing by comparing the prices of components with the cost of a new or remanufactured unit.