BOOM
LIGHT
SWITCH
BOOM
LIGHT
TM 9-4940-568-20
2-192
Table 2-21. Crane Troubleshooting (CONT).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
BOOM LIGHT IS INOPERATIVE
1. BOOM LIGHT DOES NOT WORK.
NOTE
Make sure the FRS 24 VDC electrical system is functioning properly.
Verify that boom light does not work in any of three positions (DIM, MID, and BRT). If
light works in one or more positions, go to Malfunction 2.
Test 1.
With the boom light switch in the DIM, MID, BRT position, check for voltage at the
red wire on boom light.
If voltage is present, remove black wire from boom light and check continuity from
black wire to a known good ground. If continuity is found, replace lamp. If no
continuity is found, repair or replace black wire. Refer to paragraph 3-16 in this
manual.
If no voltage is found, go to Test 2.
Test 2.
Check for voltage at wire #2 behind access plate on boom light wire spool.
If voltage is present, repair or replace boom light spool wire #2 from spool to boom
light. Refer to paragraph 3-16 in this manual.
If no voltage is present, go to Test 3.
