B.O. Service Condition (B.O. Stoplight)
B.O. stoplight malfunctioning.
B.O. stoplight fails to operate in any B.O. mode. Do steps 1 thru 11.
Remove all jewelry such as rings, dog tags, bracelets, etc. If jewelry contacts a metal surface a direct
short may result in instant heating of tools, damage to equipment, and injury or death to personnel.
Loosen six screws (1) and remove stoplight cover (2). Remove B.O. stoplight lamp (3). Place red lead
of multimeter in socket and black lead to ground. Turn MASTER switch ON, press B.O. MARKER
key and ENTER key of main light switch. Depress stoplight switch (vehicle brake) and check for
voltage. Turn MASTER, main lighting and stoplight switches OFF. If voltage is present, replace lamp
(see WP 0179 00). If voltage is not present, go to step 2.
Install B.O. stoplight lamp (3), stoplight cover (2), and tighten six screws (1). Remove two screws (4)
and two lockwashers (5) and remove hydraulic access cover (6). Disconnect wire 23 of bulkhead to
master relay and left and right taillight wiring harness from right taillight assembly. Place red lead of
multimeter in wire 23 and black lead to ground. Turn MASTER switch ON, press B.O. MARKER key
and ENTER key of main light switch, apply brakes, and check for voltage. Turn MASTER and main