TM-9-2320-272-23-2

TRUCK, 5-TON, 6X6, M939, M939A1, AND M939A2 SERIES TRUCKS (DIESEL)

TECHNICAL MANUAL; FIELD MAINTENANCE MANUAL; VOLUME 2 OF 5

SEPTEMBER 2012

TM-9-2320-272-23-2 - Page 304 of 1417

FIELD MAINTENANCE

NG50: CHARGING CIRCUIT TESTS

INITIAL SETUP:

Personnel Required

(2)

References

Volume 1, WP

0089

Volume 1, WP

0090

WP

0202

WP

0296

References (cont.)

WP

0297

WP

0300

WP

0301

WP

0302

WP

0349

WP

0350

Volume 5, WP

0780

TROUBLESHOOTING PROCEDURE

NG50: CHARGING CIRCUIT TESTS

STEP

WARNING

Turn vehicle engine off.

1.

Check drivebelt.

Refer to No Alternator Output troubleshooting 60 amp (Volume 1, WP

0089), 100 amp (Volume 1,

WP

0090), to check alternator/generator drive belts for proper tension.

CONDITION/INDICATION

Are drivebelts OK?

DECISION

YES - Go to Step (2).

NO - Replace drivebelts M939/A1 (WP

0302), M939A2 (WP

0296). After completing repair, rerun GO-Chain

tests to verify problem is solved and no other problem exists.

TM 9-2320-272-23-2

0201

0201-1