TM 9-2320-289-20
Table 2-4. Electrical Troubleshooting (Con’t)
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
5.
ALL TRUCK
Step 1.
Step 2.
Step 3.
Step 4.
Step 5
BATTERIES/CHARGING/SYSTEM
ELECTRICAL SYSTEMS INOPERATAVE
Check batteries for proper charge and electrolyte level. (See paragraph 4-39)
Voltage between ground and positive (+) terminal of rear battery should be 24.0.
Service replace.
Notify your supervisior if non-maintenace free batteries
require
service.
Check 12 volt bus bar for loose connections.
Tighten loose connections.
Check alternator belt tension. (See Appendix E)
Remove and clean all battery cable and clamp connections.
Replace worn or damaged battery cables and clamps. (See paragraph 4-38)
Check voltage between positive and negative terminal boards where battery cables
connect. Voltage should be 24.0.
If voltage is not correct, trace circuit to batteries. (See wiring diagram F-1 or
F-2)
5.1. GENERATOR LIGHT DOES NOT COME ON
WITH KEY IN “ON” POSITION BEFORE ENGINE IS
STARTED (ALL MODELS EXCEPT M1010)
Step 1.
Trace all circits from generator to generator light in instrument panel (including
fuse, bulb, arm relay}. (See wiring diagram F-11)
If circuits are good, replace alternator. (See paragraph 4-2)
6. GENERATOR LIGHT REMAINS ON OR TURNS ON DURING OPERATION (ALL EXCEPT M1010)
Step 1.
Check engine idle speed. (See paragraph 3-25)
Step 2.
Disconnect connector from left alternator (if “GEN 1“ light is on) or right alternator (if
“GEN 2“ light is on). Turn key to “RUN” position.
If generator light is not on, trace circuit from alternator connector to generator
Iight in instrument panel. (See wiring diagram F-11) If circuit is good, replace
alternator. (See paragraph 4-2)
If generator light is on, trace circuit from alternator connector to generator light
if instrument panel. (See wiring diagram F-9)
Change 2
2-59
