ELECTRICAL WIRING REPAIR

TM5-4120-384-14

ELECTRICAL WIRING REPAIR - G E N E R A L .

4-20.

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

Determine the proper

be appropriate for emergency field repairs.

size and length of wire, or the terminal, or connector to be used

for replacement by referring to Table 4-3, "Wire List", and to the

wiring diagram figure 4-4.

Soldering Connections.

Wire connections must be made

mechanically sound before they are soldered: solder alone does not

Joining surfaces

provide sufficient strength to prevent breakage.

If a

of connections to be soldered must be clean and bright.

separate flux is used, it should conform to Specification MIL-F-

14256, rosin base flux, item 6, Appendix E and should be brushed

If a flux-core solder is used, it

onto the joint before soldering.

should always be rosin-core electrical solder.

If an uncored

solder is used, it should be a lead-tin solder, item 7, Appendix E

Wires should always be

conforming to Specification QQ-S-571.

heated to the point at which the solder will melt completely and

Excessive build-up of solder

flow into all parts of the joint.

"gobs" on the joint should be avoided or removed.

Insulating Joints.

The preferred method of insulating

To apply,

electrical joints is by the use of heat-shrink tubing.

cut a piece of heat-shrink tubing of suitable diameter to a length

of 1 inch (2.5 cm) for covering joints at terminals or connectors,

or to a length about 1/2 inch (1.3 cm) longer than the joint to be

Slide the tubing over the wire before making the joint.

insulated.

After the joint is made, slide the tubing so that it covers the

joint, and shrink in place with moderate heat.

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 joint 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, and sliding on a piece of insulation tubing as described

Hold the ends parallel and facing opposite directions then

above.

Solder

twist each end around the other wire at least three turns.

and apply insulation as described above.

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 (2.5 cm) piece of heat-shrink

Insert

tubing (if the terminals are of the uninsulated type).

wire-end into the shank of the terminal.

Crimp the shank and

install heat-shrink tubing, if necessary.

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