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TM 5-4120-287-15
CHAPTER 6
ELECTRICAL SYSTEM REPAIR INSTRUCTIONS
Section I.
REMOTE CONTROL BOX ASSEMBLY
6-1.
General
The remote control box assembly (figs. 2-2 and
6-1) consists of a 5-gang, 4-posrtion selector
switch (air conditioning switch) and a 5000-
ohm variable resistor (temperature control),
as described in paragraph 2-8 a.
6-2.
Removal
a.
Set master circuit breaker to OFF posi-
tion.
b.
Remove remote control wiring harness
plugs P102 and P103 from electrical tray re-
mote control receptacle J102 and remote con-
trol box assembly receptacle J103, respectively.
c.
Remove remote control box assembly
from mounting site (para 338 a).
6-3. Testing
Using a multimeter set to read 10,000-ohms
resistance, test the remote control box as fol-
lows:
a.
Temperature Control Variable Resistor.
When testing the temperature Control Variable
Resistor perform the following:
(1)
Turn temperature control knob to
COOL position.
(2)
Connect multimeter test leads to re-
mote control box receptacle J103 terminals B
and H.
(3)
Slowly turn temperature control
knob to warm position; observe that multim-
eter indicating pointer moves smoothly from
0 to 5000-ohms reading.
(4)
If resistance range is not 0 thru
5000-ohms, or if pointer moves erratically
through range, the temperature control varia-
ble resistor (R3) is defective and must be
replaced.
6-1
b.
Air Conditioning Switch. When testing
the air conditioning switch perform the
following:
(1)
Turn temperature control knob to
COOL position.
(2)
With multimeter test leads con-
nected to remote control box assembly recep-
tacle J103 terminal sets listed in table 6-1.,
check air conditioning switch in WARM, OFF,
VENT, and COOL positions for conditions
listed in tablt 6-1.
Table 6-1.
Air Conditioning Switch rest
Multimeter test
Air conditioning switch net to
leads at J103
terminal sets
Warm
Off
Vent
Cool
A-E
0
0
0
0
A-F
C
0
0
0
B-D
C
0
0
C
B-H
V
V
V
V
C-J
0
0
0
C
C-L
C
0
0
0
D-H
V
0
0
V
D-K
0
0
C
C
0-Multimeter indicates open circuit between terminal set
C-Multimeter indicates continuity between terminal 9t
V-Multimeter Indicates continuity between terminal sets when
temperature control dial is in COOL position. and SOOG-
ohms resistance when temperature control dial is In W ARM
position.
(3)
If any one of the terminal sets tested
in the four switch positions does not give a
multimeter reading as indicated in table 6-1,
the air conditioning switch (S2) is defective
and must be replaced.
6-4.
Remote Control Box Assembly Repair
a.
Disassembly. Disassemble remote control
box assembly in the numerical sequence as
illustrated in figure 6-1. Remove hardware
only as required to replace defective part.
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