How to Fix a Broken Wire in the Ignition Coil Adapter Harness
A faulty ignition coil adapter harness is one of the common causes of ignition failure in automobiles. Typically, a malfunctioning harness must be replaced, but if the damage is relegated to just one wire in the harness it can still be repaired.
Difficulty level: Moderate
What you'll need:
- Flat screwdriver set
- Wire harness repair kit
- Small pick
- Crimping tool
- Heat shrink tubing or silicone tape
Step 1: Turn off the engine and disconnect the harness from the ignition coil.
Step 2: Using a small screwdriver or pick to disengage the retainer locking the pins in place inside the harness.
Step 3: With the connector against the terminal, insert a pick into the connector and press on the locking clip until it slides into the unlock position. Make sure that the pick does not come in contact with the terminal itself to avoid damaging it.
Step 4: Gently pull out the terminal from the connector. If the terminal does not budge easily, press the terminal against the connector again and repeat the process until the terminal comes out.
Step 5: Measure the size of the wire to determine the correct type of replacement terminal you will need.
Step 6: Cut the old terminal from the harness. Make sure to cut a length that's the same with the replacement terminal. If you cut too long or too short, the wire might become loose or short circuit.
Step 7: Strip 8 to 10 mm of insulation from the wire. Use only a wire stripper tool to remove the insulation, as a knife may nick or cut the strands of wire.
Step 8: Slide a piece of heat shrink tubing onto the wire to be spliced.
Step 9: Take an appropriately-sized splice from the repair kit and insert the replacement wire and the harness wire until they overlap with one another. Make sure that the splice only covers the stripped wire and not the insulation.
Step 10: Position the crimping tool on the center of the splice and lightly squeeze until the jaws of the tool come in contact with one another.
Step 11: Solder the completed splice. Make sure that the wires and splices are clean and use only the right amount of solder. Take note that any excess buildup of solder may cause it to snag on a nearby object and cause the solder to come loose.
Step 12: Position the heat shrink tube you slid in earlier in the wire on the middle of the splice. Then use a heat gun to shrink the tube tightly into place.
Note: If heat shrink tubing is not available, you can also use silicone tape. Wrap the tape tightly around the wire until it completely covers the splice.
Step 13: Push the terminal into the connector until you hear a clicking sound. Pull the wire gently to check if it is locked in place. If the wire comes loose, push the terminal into the connector again. If the terminal refuses to lock after several attempts, replace it with a new one.
Step 14: Close the retainer on the terminal and secure the repaired wire onto the harness.