STATIC TEST PROCEDURES

TM 9-2920-257-30&P

d. Run the full-load Test at 5000 RPM. Increase load to the rated output +/- 10% and refer to Table 2-5.

Table 2-5. FULL-LOAD TEST DIAGNOSIS

AMPS

VOLTS

DIAGNOSIS

TEST BENCH BATTERY DISCHARGED OF DEFECTIVE.

HIGH

LOW

ALLOW TO CHARGE OR REPLACE.

HIGH

NORMAL

CHARGING SYSTEM OKAY.

STOP TEST. REGULATOR AND /OR FIELD COIL MUST

HIGH

BE REPLACED. GO TO STATIC TESTS.

GENERATOR AND/OR REGULATOR MUST BE

LOW

REPAIRED OR REPLACED.

LOW

NORMAL

INCREASE LOAD

STOP TEST. BENCH MALFUNCTION OR WIRING

LOW

HIGH

ERROR.

2-8. STATIC TEST PROCEDURES

a. Perform static tests on the partially disassembled generator to confirm component failure indicated by On-Vehicle

test and bench tests.

b. Complete all static tests before repairing and assembling the generator.

c. Remove pulley and rear housing to perform the following checks in accordance with paragraph 3-4b, steps 1 thru

d. Refer to ohmmeter readings on multimeter.

e. Static Checks:

(1) Output Transistor - Do not check output transistor. If dynamic test indicates regulator or field coil failure and

field coil is good, replace the regulator. (refer to step 3, field coil)

(2) Clamping Diode - [1] Set ohmmeter to X100 scale and make sure ohmmeter is zeroed. [2] Disconnect the

regulator. [3] Connect one multimeter lead to pin E. [4] Connect the other lead to pin B and observe

ohmmeter reading. In one direction the ohmmeter should read less than 600 ohms, in the other direction

the ohmmeter should read very high. If ohmmeter reads less than 600 ohms in both directions (short) or

very high in both directions (open) clamping diode is defective and regulator must be replaced.

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