On-Vehicle Check - CS-Generator

TOOL REQUIRED:
J 39200 Digital Multimeter or equivalent

When the CS charging system is operating normally, the voltmeter will read between 11 volts and 16 volts when the engine is running. If the voltmeter operates abnormally, or if an undercharged or overcharged battery condition occurs, the following procedure may be used to diagnose the charging system. Remember that an undercharged battery is often caused by accessories being left on overnight, or by a hood or instrument panel compartment lamp that stays on.

Noise from a generator may be caused by a loose drive pulley, loose mounting bolts/screws, worn or dirty bearings, faulty diode or faulty stator. A magnetic whining noise may be heard from vehicles equipped with the CS - 130D generator. This is considered a normal condition.
To avoid damage to the electrical equipment, always observe the following precautions:
- Do not reverse connections to generator.
- Do not short across or ground any of the terminals in charging circuit, except as directed by instructions.
- NEVER disconnect generator "BAT" terminal with generator operating.
- When connecting a battery charger, or connecting battery to battery, refer to Battery.
- In some vehicles, a voltmeter may be used instead of the indicator lamp. In this case, steps 1 through 4 pertaining to faulty indicator lamp operation, should be omitted from troubleshooting procedure.
- Do not attempt to disassemble CS-13OD generator. Damage to generator could result.

Trouble in the charging system will show up as one or more of the following conditions:
- Faulty voltmeter operation.
- Undercharged battery, as evidenced by slow cranking or dark hydrometer.
- Overcharged battery, as evidenced by spewing of electrolyte from vents or a yellow hydrometer.

To diagnose the CS-13OD or CS-144 charging system, use the following procedure:
1. Visually check serpentine drive belt and wiring.
2. Battery undercharged or overcharged (voltage lower than 11 volts or higher than 16 volts).
A. Detach wiring harness connector from generator.
B. With ignition switch "ON" and engine not running, connect J 39200 as voltmeter from ground to "L" terminal in wiring harness connector. Connect to "F" or "I" terminal for gage equipped vehicles. At least one terminal should have battery voltage.
C. Zero volts indicates open circuit between terminal and battery. Correct as required.
D. Reconnect harness connector to generator.

CAUTION: Disconnect battery negative cable before installing or removing a series-type ammeter at generator battery terminal.

CAUTION: Refer to "Caution".

E. Install ammeter at generator output terminal. With load off, install carbon pile load test across battery terminals. Start engine and run at 2500 RPM. Make sure this is done at ambient temperature.
F. Measure voltage across battery, using J 39200. If voltage is above 16 volts, replace or repair generator.
G. Turn on accessories and load battery with carbon pile to obtain maximum generator output. Maintain voltage at 13 volts or above. Use ammeter to check amperage. Compare output to ampere rating in "Specifications".
- If within 15 amps of rated output, generator is OK.
- If not within 15 amps of rated output, repair or replace generator