1. STARTING & CHARGING SYSTEM DIAGNOSIS
Battery
Starter
Alternator

2. Test Equipment VAT–40 & AVR Voltmeter Ammeter
Carbon-pile variable resistor

3. Safety Issues Batteries can explode if sparks occur around them.
Battery acid is very corrosive. It can burn skin and cause blindness.
Remove negative battery cable if making any large repairs.

4. Battery Identification
Conventional Lead Acid (Cap Battery or Deep Cycle)
Maintenance Free
AGM (Absorbed Glass Mat)

5. Battery Testing Battery capacity or load test. Battery drain test.
Hydrometer test. (Cap batteries only)
Special Testing for AGM Batteries (Absorbed Glass Mat)

6. Battery Load Test Discharge battery ½ cold cranking amps. Battery + -
ammeter
voltmeter
Carbon pile
>9.6v
½ CCA
Turn resistor
to get amperage
(artificial load)

7. On the Car Connections

8. Battery Services Clean battery case Clean battery terminals
Check proper hold down
Charging batteries
Jump starting
Replacing batteries

9. Cleaning Batteries

10. Battery Charging Standard Slow Charger Fleet Battery Charger
2 – 12 amp capacity.
Fleet Battery Charger
high amps can jump and
fast charge.

11. Jumping or Boosting a Dead Battery
Positive to Positive
Negative to Ground

12. Starting System Testing
Starter load or draw test.
Starter voltage drop.
Cable voltage drop.
Solenoid voltage drop.

13. Starter Draw Test ammeter voltmeter Measure while cranking engine
Note: ammeter in series and voltmeter in parallel.

14. On the car connections

15. Battery Cable Test (Voltage drop)
voltmeter
0.5v max.
voltmeter
Measure while
cranking engine
0.2v max.
Note: Voltmeters to be set at low volt scale.

16. Testing the Solenoid (voltage drop)
Measure while
cranking engine.
voltmeter
0.2v max.

17. Starter Bench Test

18. Installing a New Starter
Safety tip: Always remove negative battery terminal.

19. Alternator/Regulator Testing
Alternator output test.
Voltage regulator setting.
Full field test.

20. Alternator Output (amps)
Run engine at 1500 –2000 rpm.
Battery
To vehicle load
amps - +
Read output
here.
Carbon pile
Amp rating
on alternator
Alternator
Adjust to max.
alternator output
(artificial load)

21. On the Car Connections

22. Voltage Regulator Setting
Run engine at 1500 –2000 rpm.
Battery
To vehicle load - + v
Voltmeter
Carbon pile
Alternator
Quickly load alternator
and back off.

23. Full Field an Alternator
When you have a dead charging system use this test to
determine if the alternator is at fault or the regulator
is at fault.
The test basically puts full battery voltage to the field
winding in the rotor of the alternator. If the alternator
is OK it will put out maximum output and the regulator
is the problem. If no output is still noticed the alternator
is faulty.

24. Full Fielding This will build a large magnetic field in the
field coil.

25. Diode Scope Pattern