ELECTRICAL TROUBLESHOOTING - continued - TM-9-2320-386-24-1-10095

TM 9-2320-386-24-1-1

0012 00

Electrical Troubleshooting (Contd)

MALFUNCTION

TEST OR INSPECTION

CORRECTIVE ACTION

NOTE

Voltage regulators in both the 100-amp and 60-amp charging

systems regulate battery voltage to 28.0 0.2 Vdc.

The 100-amp voltage regulator is separate from the 100 amp

alternator.

Battery voltage fluctuations are not to go above 28.5 Vdc or less

than 27.5 Vdc as headlights are turned ON, OFF, and ON with

engine running at 1200 rpm.

For test purposes only, charging voltage across batteries can be

varied between 26.0 to 30.0 Vdc with engine running at 1200 rpm

and headlights off.

Step 1. Turn off engine.

Step 2. Open door of battery compartment. Remove batteries onto running board

(TM 9-2320-386-10).

Step 3. Use multimeter to check battery for voltage.

Step 4. Start engine (TM 9-2320-386-10).

Step 5. Set engine speed at 1200 rpm.

Step 6. Turn ON vehicle headlights and accessories.

Step 7. Use multimeter to check battery voltage. Normal charging voltage on batteries is

28.0 0.2 Vdc.

CAUTION

Do not puncture waterproof covering on cable between alternator

and voltage regulator to make voltage checks. The cable will be

unserviceable.

a. If battery voltage measures between 24.0 and 26.0 Vdc and alternator has no or very

weak output, replace alternator (Prestolite) (WP 0089 00) or (Leece-Neville)

(WP 0090 00).

b. If battery voltage measures between 26.0 to 30.0 Vdc, adjust voltage regulator (if

equipped with adjustment screw). If charging voltage across batteries cannot be

adjusted to 28.0 0.2 Vdc, replace voltage regulator (WP 0279 00). If charging voltage

across batteries can be adjusted to 28.0 0.2 Vdc, go to step 8.

Step 8. Check voltage regulator stability.

Go to malfunction 5, test 2, step 7.

END OF TESTING!

11. BATTERIES NOT CHARGING PROPERLY (BATTERY GAUGE IN YELLOW OR RIGHT-HAND RED)

NOTE

If STE/ICE is available, perform NG50 Charging Circuit Tests

(WP 0017 00).

Test 1. Check for loose alternator mounting or missing drivebelt.

a. Tighten loose mounting hardware.

b. Replace missing drivebelt (WP 0084 00).

Test 2. Test battery voltage.

Go to malfunction 10, test 2.

0012 00-12