TM 9-2330-384-14&P
Table 4-2. Unit Troubleshooting Procedures (Con't).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
2.
ALL LIGHTS ON A CIRCUIT DO NOT OPERATE
WARNING
When troubleshooting an electrical malfunction, ALWAYS disconnect
intervehicular cable from semitrailer. Failure to follow this warning may
create a spark and explosion, resulting in serious injury or death to
personnel.
NOTE
Refer to paragraph 4-30 to determine routing of electrical wires and
location of electrical components.
Refer to Table 4-3 to determine which lights operate off same circuit
breaker circuit.
To ensure an accurate reading, probes of multimeter must contact bare
wire and unpainted metal surfaces.
Step 1.
Troubleshoot tractor electrical system (see TM 9-2320-273-20 or TM 9-2320-
283-20).
Step 2.
Check circuit across circuit breaker posts.
If there is continuity, circuit breaker is O.K. Go to step 3. If at circuit breaker #3,
#4, or #9, go to step 4.
If there is no continuity, replace circuit breaker (see paragraph 4-16). If
malfunction still exists, go to step 3. If at circuit breaker #3, #4, or #9, go to
step 4.
NOTE
Perform step 3 if at circuit breaker #1, #2, #5, #6, #7, or #8.
Check continuity in wire between circuit breaker post and pin at front of 12-volt
Step 3.
electrical connector.
If there is continuity, that wire is O.K. If at circuit breaker #1, #2, #5, or #6, go
to step 7. If at circuit breaker #7 or #8, go to step 5.
If there is no continuity, replace wire (see paragraph 4-17). While replacing
wire, visually inspect for a bent or corroded connector pin. If pin is damaged,
replace electrical connector (see paragraph 4-17). If malfunction still exists,
and if at circuit breaker #1, #2, #5, or #6, go to step 7. If at circuit breaker #7 or
#8, go to step 5.
4-17
