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© Unitec New Zealand 1 Faulty Starting System Symptoms No Cranking Slow Cranking Abnormal Noise Overheating of Cables.

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Presentation on theme: "© Unitec New Zealand 1 Faulty Starting System Symptoms No Cranking Slow Cranking Abnormal Noise Overheating of Cables."— Presentation transcript:

1 © Unitec New Zealand 1 Faulty Starting System Symptoms No Cranking Slow Cranking Abnormal Noise Overheating of Cables

2 © Unitec New Zealand 2 Engine does not crank (Solenoid or relay does not click) Dead battery Loose, corroded or broken connections Corroded battery terminals (lights will usually light) Faulty ignition switch Faulty neutral safety switch or clutch switch (To test: push on brake pedal, hold key in start position and move shift lever or clutch pedal) Defective starter switch, relay or solenoid.

3 © Unitec New Zealand 3 Engine will not crank (Solenoid or relay clicks) Low or "dead" battery Corroded battery terminals or cables Defective starter solenoid or relay Defective starter motor (if current is passed through relay or solenoid)

4 © Unitec New Zealand 4 Starter motor cranks slowly Low battery Loose, corroded or broken connections Cable size too small Internal starter motor problems Engine oil too heavy Ignition timing too far advanced

5 © Unitec New Zealand 5 Starter spins, but will not crank engine Broken starter drive gear Broken flywheel teeth Noisy starter motor Starter mounting loose Worn starter drive gear or flywheel teeth Worn starter bushings

6 © Unitec New Zealand 6 On Vehicle Testing Cranking speed Cranking Voltage- should be > 9.6V Voltage Drop is indication of excessive résistance, loose or dirty contacts Should be < 0.25 to 0.5V Current Draw – 4 cylinder engine A max.

7 © Unitec New Zealand 7 Current Draw Test No Current draw – open circuit High current draw –Short circuits –Poling –Tight bushes –Insufficient thrust clearance –Engine not turning freely Low current draw –High resistance –Burnt solenoid contacts –Dirty/ burnt commutator and brushes

8 © Unitec New Zealand 8 Starter Tests off Vehicle Bench Test- no special tester needed Lock Torque or Stall Test- normally carried out after an overhaul

9 © Unitec New Zealand 9 Bushes and Bearing Check and Inspect Poling – armature rubbing on the pole shoes Bushes- for excessive Bearings – roughness and bumpiness (reduction gear type) New bushes should be immersed in oil for one hour

10 © Unitec New Zealand 10 Brushes and Bush holder Measure brush length – it should be within the specifications Check for sticky brush ( in its holder) Check brush spring tension Positive brushes must be insulated –Infinity reading with the brush holder and brush plate

11 Positive Brushes must be insulated © Unitec New Zealand 11

12 Measure Brush length © Unitec New Zealand 12

13 © Unitec New Zealand 13 Solenoid test Use half the rated voltage Pull in test –Connect battery power to terminal S and M –Plunger should pull in Hold in test –Push the plunger in –Connect battery power to terminals S and solenoid body –Release the plunger and it should remain held. Return Test –Plunger should return to normal position once the power is disconnected

14 Hold in Test © Unitec New Zealand 14

15 Pull In Test © Unitec New Zealand 15

16 © Unitec New Zealand 16 Armature Check for burning and overheating Check for bend in the shaft on a ‘v’ block Check for poling Test for short circuit on a growler- blade will vibrate on the short circuit winding. Test the windings for Open circuit -on the commutator segments –Use a ohmmeter or light tester (30V) Test short to ground- from commutator to shaft and armature body –Use ohmmeter

17 Measure Commutator diameter © Unitec New Zealand 17

18 Armature Ground test © Unitec New Zealand 18

19 Commutator continuity test © Unitec New Zealand 19

20 Commutator test with 42 V © Unitec New Zealand 20

21 Growler test © Unitec New Zealand 21

22 Armature Run -Out Test © Unitec New Zealand 22

23 © Unitec New Zealand 23 Field Coil Check for insulation damage Test for open circuit- between the brush and positive terminal of the field –use ohmmeter or test light Test for short to ground – field coil to the housing –use test light

24 Field Coil to Short to Ground Test © Unitec New Zealand 24

25 © Unitec New Zealand 25 Clutch assembly It should lock on one direction and turn freely in the other direction Check for smooth movement along the splines.

26 One way clutch test © Unitec New Zealand 26

27 © Unitec New Zealand 27 Armature Thrust Clearance Use filler gauge to measure the clearance If not right adjust it using shims

28 © Unitec New Zealand 28 Pinion Clearance Disconnect SM terminal from the solenoid Apply battery power to S and SM terminal of the solenoid Pinion should move out without the armature spinning. Check the clearance

29 Pinion Clearance © Unitec New Zealand 29

30 Test Bench © Unitec New Zealand 30


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