For a pigtail connector, twist it firmly to lock the wires. Slide heat shrink tubing over the connection and heat it. For OEMs, cable assembly troubleshooting and wire harness troubleshooting help maintain quality, reduce field failures, and avoid production delays. Electrical systems in vehicles, fire trucks, generators, boats. Wire harness failures often occur due to several factors: Poor design: If the wire harness isn't designed with the end application in mind, problems can arise quickly. Improper. This video demonstrates the repair of automotive wiring harness connectors, specifically the de-pin and re-pin method used for common pigtails, which can often be damaged, corroded, or broken. Key. A faulty pigtail can lead to anything from intermittent malfunctions to complete system failure, even posing a significant safety hazard.