AT 121 Chapter 7a – Charging SystemsName: _________________________________ Group: _________________________Date: __________________________________Symptom ChartCondition Possible SourcesCharging system malfunction (high or low system voltage)- A circuit fuse link.- B+ circuit fuse links.- Generator.- PCM/Regulator- Loose/Damaged Drive BeltDead battery or battery will not stay charged- Defective Generator.- Defective Battery.- B+ Circuit.- High key-off load. (Parasitic Drain)- Loose, corroded terminal(s).Charging system warning indicator malfunctioning (light on with engine running, light off with key on engine off, light on with key off)- Charging system warning indicator bulb.- Instrument cluster.- Generator.- PCM/RegulatorGenerator is noisy- Loose bolts/brackets.- Drive belt.- Generator BearingsRadio interference- Generator.- Wiring/routing - poor grounds- In-vehicle entertainment system.Tools you will need:2001 Honda Accord or 1997 Acura 2.2 CL - Alternator Specifications – 80 Amps at 2000 RPM – 70 Deg F.Factory Shop ManualStraight EdgeDVOMARBST TesterAmp Probe SECTION 1 Inspect Accessory Drive Belt Condition and Tension. Incorrect belt tension will cause undercharging. A loose belt will slip and squeal. Anover tightened belt will cause will cause bearing damage. An oily belt will slip, but bequiet. Misaligned drive belts will cause fraying and constantly be “thrown off”. Tension Spec? _____________________________ Is there oil on the belt? _________________________ (Yes/No) Drive the belt show signs of chunking? ________________ (Yes/No) Are the pulleys in alignment? ______________________ (Yes/No) Is the accessory drive belt OK? __________________ (Yes/No) SECTION 2 Check Generator ConnectionsPoor generator connections will cause high resistance in the B+ circuit. This will cause a voltage drop. Are the generator connections (B+, Ground, and Regulator Connections) clean and tight? __________________ (Yes/No)1 SECTION 3 Charging System Voltage With the engine running, monitor the voltage at the battery.  Is the battery voltage between 13 and 15 volts? __________ (Yes/No) What is the battery voltage? ____________________ When finished have the instructor sign off on your work. _____________________________________ SECTION 4 Voltage Drop TestsOutput Circuit – Insulated (Power) Side Place one end of the meter at the B+ terminal of thealternator. Place the other end of the meter at the (+) terminal of thebattery. Run the vehicle with no loads at 2000 rpm The voltage drop should be less than 0.5 volts. The voltage drop is _______________________ If the voltage drop were greater than 0.5 volts this wouldindicate high resistance in the B+ circuit of the alternator. Acorroded wire or terminal end could be the cause.Output Circuit – Ground Side Place one end of the meter at the case of the alternator. Place the other end of the meter at the (-) terminal of thebattery. Run the vehicle with no loads at 2000 rpm The voltage drop should be less than 0.2 volts.  The voltage drop is _______________________If the voltage drop were greater than 0.2 volts this wouldindicate high resistance in the ground circuit of the alternator. A corroded wire or terminal end could be the cause as well as apoor engine ground or loose alternator mount. SECTION 5 Checking for Diode Ripple (AC voltage) (no, not THAT Ripple!) Checking Ripple Voltage Ripple voltage or (AC voltage) can be measured by switching the DVOM to AC and connecting the black lead to a good ground and the red lead to the B+ on the back of the alternator. A good alternator should measure less than .5 VAC with the engine running. A higher reading indicates damaged alternator diodes.Voltage A/C __________________ Pass/Fail? _________________________2QAt what RPM should the voltage drop tests be done at? __________________________A voltage drop of more than ____________________ indicates high resistance in the B+ circuit.A voltage drop of more than ____________________ indicates high resistance in the ground circuit.When checking for AC diode ripple, if the AC voltage is more than _______________ volts ___________ the diodes in the alternator may have failed.What will be the end result of an over tightened belt? _______________________________________What would cause the belt to slip, even if it were tight? _______________________________________When would one hear a loose alternator belt? _____________________________________________Name 5 things that would cause a generator to undercharge: ______________________________________________________________________________________________________________________________________________________________________________________________________ When finished have the instructor sign off on your work. _____________________________________ SECTION 6 Alternator Load TestingFollowing the procedure demonstrated to you by the instructor test the alternator using the ARBST tester.ARBST Tester Results; Volts _____________________ Amps ______________________ Diodes ___________________ Leaving the ARBST tester hooked up. With the engine running, turn the A/C on, the blower motor on high speed and the headlamps on high beam. Increase the engine speed to approximately 2,000-rpm. The voltage should increase a minimum of 0.5 volt above the base voltage. The total amps should be close to the maximum of the alternator total output. Fact is this test can be done with any inductive amp meter.Volts _____________________ Amps ______________________If voltage were low – the next step would be to full field the alternator.Full Fielding the Alternator WARNING! DO NOT FULL FIELD ALTERNATOR FOR MORE THAN 10 SECONDS AT A TIME! Ground the “F” terminal Results - Volts _____________________This test bypasses the regulator and sends full field voltage and current to the rotor assembly. Voltage should be about 17-18 volts. If not a damaged rotor or stator is possible. If voltage DOES go up, but falls back to a voltage lower than 13 volts –the regulator is bad.3If the voltage does not go up on a full field test, what is at fault? ________________________________________If the voltage does go up on a full field test, but then falls below 13 volts what is at fault?_____________________________ When finished have the instructor sign off on your work.