TM 9-2330-271-14&P
b.
Removal (fig. 6).
(4) On the XM822 semitrailer, a microswitch for
the blackout lights is located in each of the three outside
(1) Remove four nuts (18), washers (19), and
door jambs. Two override switches are provided to
bolts (20) securing receptacle and cover (17) to chassis
bypass the blackout lights. Four three-way switches are
frame. Remove receptacle.
located in the laboratory compartment and four other
(2) Unsolder wires at rear of receptacle.
c. Cleaning and Inspection.
three-way switches are located in the rear compartment.
A one-way switch is located in the utility compartment.
(1) Clean all parts with an approved cleaning
b. Removal of Dome Light Switch, 24 Volts,
solvent (paragraph 3-3b). Dry thoroughly.
XM574, XM574E1, XM654, XM738, XM739, XM739E1,
(2) Inspect for cracks, breaks and other
XM822, XM844, XM845, XM847, XM848, XM849,
damage.
XM850.
(3) Replace defective parts.
d. Installation (fig. 6).
(1) Remove four screws (four rivets for the
(1) Solder wires to terminals at rear of
XM822) securing switch to wall.
receptacle in accordance with wiring diagram (figs. 4-15,
(2) Detach wires and remove switch c
4-16).
Installation of Dome Light Switch, 24 Volts (1) Attach
(2) Aline holes in receptacle (17) with holes in
wires (refer to figs. 4-8, 4-9, 4-12 through 4-14, 4-17, or
chassis and secure with four bolts (20), washers (19),
4-18).
and nuts (18).
(2) Position switch on wall and secure with four
screws (four rivets for the XM822 semitrailer).
d. Removal of Door Operated Blackout Switch,
4-17.
Semitrailer Purging Time Clock, XM822 (fig.
XM822.
(1) Remove four screws securing cover and
seal to switch housing. Remove cover and seal.
a.
General.
(2) Detach wires from switch.
(1) A time clock used in the purging of the
(3) Remove three screws securing switch
semitrailer is located on the exterior of the XM822
housing to semitrailer wall.
semitrailer at the rear, roadside, next to the power entry
(4) Remove connector securing conduit to
receptacle.
switch housing and withdraw housing.
(2) Van purging instruction is located adjacent
e. Installation of Door Operated Blackout Switch,
to the time clock.
XM822.
(3) All exterior doors have warning plates
(1) Position housing and secure conduit to
cautioning personnel to purge the van before entering.
switch with the connector.
(4) The purging circuit breaker is always ON.
(2) Secure switch housing to semitrailer wall
b. Removal of Time Clock.
with three screws.
(1) Remove four self-locking nuts and screws
(3) Attach wires to switch.
securing time clock to chassis.
(4) Position cover and seal on switch housing
(2) Unsolder wires at rear of clock and remove
and secure with four screws.
clock.
f.
Removal of Blackout Override Switch, XM822.
c. Installation of Time Clock.
(1) Remove two screws securing plate and
(1) Solder wires at rear of time clock.
switch (with guard) to junction box.
(2) Position clock and secure with four screws
(2) Loosen integral locking nut and remove
and self-locking nuts.
guard and switch.
(3) Detach wires from switch.
4-18.
Switches
g. Installation of Blackout Override Switch, XM822.
a.
General.
(1) Attach wires to switch.
(1) The XM654 semitrailer has 8 toggle
(2) Position switch and guard on plate and
switches and 37 circuit breakers, of which 30 are the 20-
secure by tightening integral locking nut.
amp type used for the 30-dome lights.
(3) Position plate with switch attached on
(2) The XM680 and XM580E1 are equipped
junction box and secure with two screws.
with 11 toggle switches and 6 micro switches.
(3) On the XM822 semitrailer, two master
switch boxes are located in the rear compartment. The
switch box at the left controls the 110-volt circuits; the
box at the right controls the 220-volt circuits. Each
switch is provided with a circuit breaker.
4-31
