All about Ford Mondeo

Starting system - testing
Engine electrical systems / Starting system - testing


Note: Before diagnosing starter problems, make sure that the battery is fully-charged, and ensure that the alarm/engine immobiliser system is not activated.

1 If the starter motor does not turn at all when the switch is operated, make sure that, on automatic transmission models, the selector lever is in Park or Neutral (УPФ or УNФ).

2 Make sure that the battery is fully-charged, and that all leads, both at the battery and starter solenoid terminals, are clean and secure.

3 If the starter motor spins but the engine is not cranking, the overrunning clutch or (when applicable) the reduction gears in the starter motor may be slipping, in which case the starter motor must be overhauled or renewed.

(Other possibilities are that the starter motor mounting bolts are very loose, or that teeth are missing from the flywheel/driveplate ring gear.)
4 If, when the switch is actuated, the starter motor does not operate at all but the solenoid clicks, then the problem lies with either the battery, the main solenoid contacts, or the starter motor itself (or the engine is seized).

5 If the solenoid plunger cannot be heard to click when the switch is actuated, the battery is faulty, there is a fault in the circuit, or the solenoid itself is defective.

6 To check the solenoid, connect a fused jumper lead between the battery (+) and the ignition switch terminal (the small terminal) on the solenoid. If the starter motor now operates, the solenoid is OK, and the problem is in the ignition switch, selector lever position sensor (automatic transmission) or in the wiring.

7 If the starter motor still does not operate, remove it (see Section 16). The brushes and commutator may be checked (see Section 17), but if the fault persists, the motor should be renewed, or taken to an autoelectrician for testing and repair.

8 If the starter motor cranks the engine at an abnormally-slow speed, first make sure that the battery is charged, and that all terminal connections are tight. If the engine is partially seized, or has the wrong viscosity oil in it, it will crank slowly.

9 Run the engine until normal operating temperature is reached, then switch off and disable the ignition system by unplugging the ignition coilТs electrical connector; remove fuse 14 to disconnect the fuel pump.

10 Connect a voltmeter positive lead to the battery positive terminal, and connect the negative lead to the negative terminal.

11 Crank the engine, and take the voltmeter readings as soon as a steady figure is indicated. Do not allow the starter motor to turn for more than 15 seconds at a time. A reading of 10.5 volts or more, with the starter motor turning at normal cranking speed, is normal. If the reading is 10.5 volts or more but the cranking speed is slow, the solenoid contacts are burned, the motor is faulty, or there is a bad connection. If the reading is less than 10.5 volts and the cranking speed is slow, the starter motor is faulty or there is a problem with the battery.


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