4-31. FLUORESCENT LIGHTING FIXTURE MAINTENANCE (ALL EXCEPT M749) (Cont).
Install starter (15) in socket, push in, and turn 1/4 turn clockwise.
Insert fluorescent lamp (12) in fixture (1) with electrodes lined up with terminals at each end. Push lamp terminal
out, snap in lamp, and release terminals which spring back over lamp electrodes.
Swing grille (17) back in place and tighten two captive screws (16).
Loosen two captive screws (16) and allow grille (17) to swing down.
Remove fluorescent lamps and starters from fixture (subpara a).
The number of fluorescent fixture mounting screws varies from semitrailer to
semitrailer. The M313 has 16, M447, M447C, and M750 center fixture hasten, while the
M750 outer fixtures have 14.
Remove screws (9) and fixture (1) from ceiling. Tag and disconnect wires (7).
CLEANING AND INSPECTION
Remove four screws (13) and cover (14) from fixture.
Inspect fixture for warpage, dents, scratches, or chipped paint. Remove dents, straighten any bent sections,
and repaint if necessary.
Inspect fixture for defective lamp terminal bracket, filter, ballast, and starter. Replace defective components.
d. BALLAST REPLACEMENT
Remove two screws (10) and nuts (11) securing ballast (8) to fixture (1).
Tag and cut wires (6) on line and load sides of ballast (8) as close as possible to splices. Remove ballast.
Position ballast (8) in place on fixture (1) and install two screws (10) and nuts (11).
Splice wires (6) together between ballast (8) and fixture (1). Remove tags.
All fluorescent light fixtures have filters except the outer fixtures on the M750 vans.
Remove two screws (2) and nuts (3) securing filter (4) to fixture (l).
Tag and cut filter wires (5) as close as possible to splices in wire (7). Remove filter (4).
Position filter (4) in place on fixture (1) and install two screws (2) and nuts (3).
Splice wires (5) together between filter (4) and fixture (1). Remove tags.