Conductor repairs are sometimes needed because of wire damage caused by electrical faults or by physical abuse. Wires may be damaged electrically by short circuits between wires or from wires to ground. Fusible links may melt from current overloads. Wires may be damaged physically by scraped or cut insulation, chemical or heat exposure, or breaks caused during testing or component repairs.
Choosing the proper size of wire when making circuit repairs is critical. While choosing wires too thick for the circuit will only make splicing a bit more difficult, choosing wires too thin may limit current flow to unacceptable levels or even result in melted wires. Two size factors must be considered: wire gauge number and wire length.
• WIRE GAUGE NUMBER
Wire gauge numbers are determined by the conductor's cross-section area.
In the American Wire Gauge system, "gauge" numbers are assigned to wires of different thicknesses. While the gauge numbers are not directly comparable to wire diameters and cross-section areas, higher numbers (16, 18, 20) are assigned to increasingly thinner wires and lower numbers (1, 0, 2/0) are assigned to increasingly thicker wires. The chart shows AWG gauge numbers for various thicknesses.
Wire cross-section area in the AWG system is measured in circular mils. A mil is a thousandth of an inch (0.001). A circular mil is the area of a circle 1 mil (0.001) in diameter.
In the metric system used worldwide, wire sizes are based on the cross-section area in square millimeters (mm 2 ). These are not the same as AWG sizes in circular mils. The chart shows AWG size equivalents for various metric sizes.
Wire length must be considered when repairing circuits because resistance increases with longer lengths. For instance, a 16-gauge wire can carry an 18-amp load for 10 feet without excessive voltage drop. But, if the section of wiring being replaced is only 3-feet long, an 18-gauge wire can be used. Never use a heavier wire than necessary, but - more important - never use a wire that will be too small for the load.
• Cut insulation should be wrapped with tape or covered with heat-shrink tubing. In both cases, overlap the repair about 1/2-inch on either side.
• If damaged wire needs replacement, make sure the same or larger size is used. Also, attempt to use the same color. Wire strippers will remove insulation without breaking or nicking the wire strands.
• When splicing wires, make sure the battery is disconnected. Clean the wire ends. Crimp and solder them using rosin-core, not acid-core, solder.
Soldering joins two pieces of metal together with a lead and tin alloy.
In soldering, the wires should be spliced together with a crimp. The less solder separating the wire strands, the stronger the joint.
Solder is a mixture of lead and tin plus traces of other substances.
Flux core wire solder (wire solderwith a hollow center filled with flux) is recommended for electrical splices.
• SOLDERING FLUX
Soldering heats the wires. In so doing, it accelerates oxidization, leaving a thin film of oxide on the wires that tends to reject solder. Flux removes this oxide and prevents further oxidation during the soldering process.
Rosin or resin-type flux must be used for all electrical work. The residue will not cause corrosion, nor will it conduct electricity.
• SOLDERING IRONS
The soldering iron should be the right size for the job. An iron that is too small will require excessive time to heat the work and may never heat it properly. A low-wattage (25-100 W) iron works best for wiring repairs.
• CLEANING WORK
All traces of paint, rust, grease, and scale must be removed. Good soldering requires clean, tight splices.
• TINNING THE IRON
The soldering iron tip is made of copper. Through the solvent action of solder and prolonged heating, it will pit and corrode. An oxidized or corroded tip will not satisfactorily transfer heat from the iron to the work. It should be cleaned and tinned. Use a file and dress the tip down to the bare copper. File the surfaces smooth and flat.
Then, plug the iron in. When the tip color begins to change to brown and light purple, dip the tip in and out of a can of soldering flux (rosin type). Quickly apply rosin core wire solder to all surfaces.
The iron must be at operating temperature to tin properly. When the iron is at the proper temperature, solder will melt quickly and flow freely. Never try to solder until the iron is properly tinned.
• SOLDERING WIRE SPLICES
Apply the tip flat against the splice. Apply rosin-core wire solder to the flat of the iron where it contacts the splice. As the wire heats, the solder will flow through the splice.
• RULES FOR GOOD SOLDERING
1. Clean wires.
2. Wires should be crimped together.
3. Iron must be the right size and must be hot.
4. Iron tip must be tinned.
5. Apply full surface of soldering tip to the splice.
6. Heat wires until solder flows readily.
7. Use rosin-core solder.
8. Apply enough solder to form a secure splice.
9. Do not move splice until solder sets.
10. Place hot iron in a stand or on a protective pad.
11. Unplug iron as soon as you are finished.
Step 1. Identify the connector and terminal type.
1. Replacing Terminals a. Identify the connector name, position of the locking clips, the un-locking direction and terminal type from the pictures provided on the charts.
Step 2. Remove the terminal from the connector.
1. Disengage the secondary locking device or terminal retainer.
a. Locking device must be disengaged before the terminal locking clip can be released and the terminal removed from the connector.
b. Use a miniature screwdriver or the terminal pick to unlock the secondary locking device.
2. Determine the primary locking system from the charts.
a. Lock located on terminal b. Lock located on connector c. Type of tool needed to unlock d. Method of entry and operation
3. Remove terminal from connector by releasing the locking clip.
a. Push the terminal gently into the connector and hold it in this position.
b. Insert the terminal pick into the connector in the direction shown in the chart.
c. Move the locking clip to the un-lock position and hold it there.
NOTE: Do not apply excessive force to the terminal. Do not pry on the terminal with the pick.
d. Carefully withdraw the terminal from the connector by pulling the lead toward the rear of the connector.
NOTE: Do not use too much force. If the terminal does not come out easily, repeat steps (a.) through (d.).
Measure "nominal" size of the wire lead by placing a measuring device, such as a micrometer or Vernier Caliper, across the diameter of the insulation on the lead and taking a reading.
Select the correct replacement terminal, with lead, from the repair kit.
Stripped insulatioin length (A)
approximately 8 to 10 mm (3/8 in.)
with new terminal
Heat shrink tube
Heat shrink tube
6. Cut the old terminal from the harness.
a. Use the new wire lead as a guide for proper length.
NOTE: If the length of wire removed is not approximately the same length as the new piece, the following problems may develop:
Too short - tension on the terminal, splice, or the connector, causing an open circuit.
Too long - excessive wire near the connector, may get pinched or abraded, causing a short circuit.
NOTE: If the connector is of a waterproof type, the rubber plug may be reused.
7. Strip insulation from wire on the harness and replacement terminal lead.
a. Strip length should be approximately 8 to 10 mm (3/8 in.).
NOTE: Strip carefully to avoid nicking or cutting any of the strands of wire.
NOTE: If heat shrink tube is to be used, it must be installed at this time, sliding it over the end of one wire to be spliced. (See Step 3, 4. B. 1. for instructions on how to use heat shrink tube.)
NOTE: If the connector is a waterproof type, the rubber plug should be installed on the terminal end at this time.
1. Select correct size of splice from the repair kit.
a. Size is based on the nominal size of the wire (three sizes are available).
Part Number 00204-34130
2. Crimp the replacement terminal lead to the harness lead.
a. Insert the stripped ends of both the replacement lead and the harness lead into the splice, overlapping the wires inside the splice.
NOTE: Do not place insulation in the splice, only stripped wire.
b. Do not use position marked "INS".
The crimping tool has positions marked for insulated splices (marked "INS") that should not be used, as they will not crimp the splice tightly onto the wires.
c. Use only position marked "NON INS".
1. With the center of the splice correctly placed between the crimping jaws, squeeze the crimping tool together until the contact points of the crimper come together.
NOTE: Make sure the wires and the splice are still in the proper position before closing the crimping tool ends. Use steady pressure in making the crimp.
2. Make certain that the splice is crimped lightly.
3. Solder the completed splice using only rosin core solder.
a. Wires and splices must be clean.
b. A good mechanical joint must exist, because the solder will not hold the joint together.
c. Heat the joint with the soldering iron until the solder melts when pressed onto the joint.
d. Slowly press the solder into the hot splice on one end until it flows into the joint and out the other end of the splice.
NOTE: Do not use more solder than necessary to achieve a good connection. There should not be a "glob" of solder on the splice.
e. When enough solder has been applied, remove the solder from the joint and then remove the soldering iron.
4. Insulate the soldered splice using one of the following methods:
a. Silicon tape (provided in the wire repair kit)
1. Cut a piece of tape from the roll approximately 25 mm (1 in.) long.
2. Remove the clear wrapper from the tape.
NOTE: The tape will not feel "sticky" on either side.
3. Place one end of the tape on the wire and wrap the tape tightly around the wire. You should cover one-half of the previous wrap each time you make a complete turn around the wire. (When stretched, this tape will adhere to itself.)
4. When completed, the splice should be completely covered with the tape and the tape should stay in place. If both of these conditions are not met, remove the tape and repeat steps 1 through 4.
NOTE: If the splice is in the engine compartment or under the floor, or in an area where there might be abrasion on the spliced area, cover the silicon tape with vinyl tape.
b. Heat shrink tube (provided in the wire repair kit)
1. Cut a piece of the heat shrink tube that is slightly longer than the splice, and slightly larger in diameter than the splice.
2. Slide the tube over the end of one wire to be spliced. (THIS STEP MUST BE DONE PRIOR TO JOINING THE WIRES TOGETHER!)
3. Center the tube over the soldered splice.
4. Using a source of heat, such as a heat gun, gently heat the tubing until it has shrunk tightly around the splice.
NOTE: Do not continue heating the tubing after it has shrunk around the splice. It will only shrink a certain amount, and then stop. It will not continue to shrink as long as you hold heat to it, so be careful not to melt the insulation on the adjoining wires by trying to get the tubing to shrink further.
Step 4. Install the terminal into the connector.
1. If reusing a terminal, check that the locking clip is still in good condition and in the proper position.
a. If it is on the terminal and not in the proper position, use the terminal pick to gently bend the locking clip back to the original shape.
b. Check that the other parts of the terminal are in their original shape.
2. Push the terminal into the connector until you hear a "click".
NOTE: Not all terminals will give an audible "click".
a. When properly installed, pulling gently on the wire lead will prove the terminal is locked in the connector.
3. Close terminal retainer or secondary locking device.
a. If the connector is fitted with a terminal retainer, or a secondary locking device, return it to the lock position.
4. Secure the repaired wire to the harness.
a. If the wire is not in the conduit, or secured by other means, wrap vinyl tape around the bundle to keep it together with the other wires.
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