TM 10-3930-641-20
ELECTRICAL SYSTEMS TROUBLESHOOTING (CONT)
(Sheet 1 of 7)
PROBLEM NO. 25
25 a.
TAIL, Sheet 4
SERVICE LIGHTS
PANEL, Sheet 5
25 b.
HEAD, Sheet 6
25 c.
FLOOD, Sheet 6
25 d.
25 e.
AUX FLOOD, Sheet 7
A general procedure can be used to troubleshoot most of the service lights. This procedure is as follows:
Read the circuit description for the particular faulty light(s) while referring to the mini-circuit diagram below the description.
1.
If all of the service lights do not work, see PROBLEM 6.
2. Use the following generalized tabular logic tree to isolate the problem (see Sheet 2).
NOTE A: All lamps are 24 volts.
NOTE B: Voltage checks are negative to ground. See page 2-57.
NOTE C. Continuity checks are made with item removed from system. See page 2-53.
NOTE D: If only one lamp will not come on, go to Step 8.
NOTE E: HEAD LIGHTS get power from a 15 amp circuit breaker rather than a fuse. Go to Step 3.
NOTE F: Fuse numbers are from left to right starting at LHIP.
NOTE G: Always replace or repair a wire with same size (gage). See WIRE LIST, page 2-61.
Go on to Sheet 2
