Section III GENERAL MAINTENANCE PROCEDURES

TM 5-4120-359-14

Section III GENERAL MAINTENANCE PROCEDURES

4-3. ELECTRICAL WIRING REPAIR GENERAL

Preferred repair methods consist of replacing wires, terminals, connectors, etc., rather than splicing wires, bending ends

to form terminals, and other make-shift procedures; although the latter may be appropriate for emergency field repairs.

Determine the proper size and length of wire, or the terminal, or connector to be used for replacement by referring to

table 4-2, "Wire List", and to the wiring diagram (figure 4-3).

a. Soldering Connections. Wire connections must be made mechanically sound before they are soldered; solder

alone does not provide sufficient strength to prevent breakage. Joining surfaces of connections to be soldered must be

clean and bright. If a separate flux is used, it should conform to Specification MIL-F-4995, Type I, rosin-alcohol flux, and

should be brushed onto the joint before soldering. If a flux-core solder is used, it should always be rosin-core electrical

solder. If an uncored solder is used, it should be a lead-tin solder, item 1 Appendix E, conforming to Specification

QQ-571. Wires should always be heated to the point at which the solder will melt completely and flow into all parts of the

joint. Excessive build-up of solder "gobs" on the joint should be avoided or removed.

b. Insulating Joints. The preferred method of insulating electrical joints is by the use of heat-shrink tubing. To apply,

cut a piece of heat-shrink tubing of suitable diameter to a one-inch length for covering joints at terminals or connectors, or

to a length about 1/2 inch (1.3 cm) longer than the joint to be insulated, and slide the tubing over the wire before making

the joint. After the joint is made, slide the tubing so that it covers the joint, and shrink in place with moderate heat.

c. Splicing Wires. To repair broken or cut wires that are otherwise sound, the mating ends can be stripped and

spliced. A commercial butt splice can be crimped onto the ends to join them, or a "Western Union" wire splice can be

made. The latter is made by stripping 1/4 - 1/2 inch (0.6 - 1.3 cm) of insulation from the wire ends, holding the ends

parallel and facing opposite directions, then twisting each end around the other wire at least three turns. Solder and apply

insulation as described above.

d. Crimping Terminals. To install a terminal on the end of a wire, strip 1/4 - 1/2 inch (0.6 -1.3 cm) of insulation from

the end of the wire, apply a one-inch piece of heat-shrink tubing (if the terminals are of the uninsulated type), and insert

wire end into the shank of the terminal. Crimp the shank, and install heat-shrink tubing, if necessary.

Table 4-2. WIRE LIST

TERMINATION

AWG

LENGTH

Wire

FROM

TERMINAL TYPE

Size

IN.

WIRING HARNESS

P2-A

MS3106R24-11S

TB4-7

MS17143-2

104.1

P2-B

MS3106R24-11S

TB4-8

MS17143-2

104.1

P2-C

MS3106R24-11S

TB4-9

MS17143-2

104.1

P2-D

MS3106R24-11S

TB4-4

MS17143-3

99.1

P2-E

MS3106R24-11S

TB4-5

MS17143-3

99.1

P2-F

MS3106R24-11S

TB4-6

MS17143-3

99.1

P2-G

MS3106R24-11S

MS25036-153

111.8

P2-H

MS3106R24-11S

TB4-3

MS17143-2

99.1

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