Transcript Starting System Service

Faulty Starting System Symptoms
• No Cranking
• Slow Cranking
• Abnormal Noise
• Overheating of Cables
© Unitec New Zealand
1
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.
© Unitec New Zealand
2
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)
© Unitec New Zealand
3
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
© Unitec New Zealand
4
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
© Unitec New Zealand
5
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 125-175 A max.
© Unitec New Zealand
6
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
© Unitec New Zealand
7
Starter Tests off Vehicle
• Bench Test- no special tester needed
• Lock Torque or Stall Test- normally carried out after an
overhaul
© Unitec New Zealand
8
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
© Unitec New Zealand
9
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
© Unitec New Zealand
10
Positive Brushes must be insulated
© Unitec New Zealand
11
Measure Brush length
© Unitec New Zealand
12
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
© Unitec New Zealand
13
Hold in Test
© Unitec New Zealand
14
Pull In Test
© Unitec New Zealand
15
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
© Unitec New Zealand
16
Measure Commutator diameter
© Unitec New Zealand
17
Armature Ground test
© Unitec New Zealand
18
Commutator continuity test
© Unitec New Zealand
19
Commutator test with 42 V
© Unitec New Zealand
20
Growler test
© Unitec New Zealand
21
Armature Run -Out Test
© Unitec New Zealand
22
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
© Unitec New Zealand
23
Field Coil to Short to Ground Test
© Unitec New Zealand
24
Clutch assembly
• It should lock on one direction and turn freely in the other
direction
• Check for smooth movement along the splines.
© Unitec New Zealand
25
One way clutch test
© Unitec New Zealand
26
Armature Thrust Clearance
• Use filler gauge to measure the clearance
• If not right adjust it using shims
© Unitec New Zealand
27
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
© Unitec New Zealand
28
Pinion Clearance
© Unitec New Zealand
29
Test Bench
© Unitec New Zealand
30