If a headlight on your Chevrolet Impala is not functioning, you may need to replace the wiring harness. The wiring harness powers the headlight and plugs into the rear of the headlight assembly. If all of your headlights are failing, you probably have a fault somewhere else in the electrical system, not in the wiring harnesses. But if no power is coming through the wiring harness or if you notice that it is weathered and bare wire is exposed, you should replace it.
Turn off your vehicle and prop open the hood.
Disconnect the negative cable from the battery's negative terminal by loosening the negative terminal nut with your crescent wrench. Setting the negative cable aside.
Disconnect the current headlight wiring harness from the back of the headlight.
Cut off the wiring harness with the wire cutter.
Strip about an inch of insulation off of the wire that the wiring harness was connected to. This action exposes the bare metal within the insulation. Strip another inch of insulation off of the cable that comes attached to the new, replacement wiring harness.
Slide the solder sleeve connector over the cable from the vehicle that had the previous headlight wiring harness on it.
Braid the exposed leads of the two wires together.
Slide the solder sleeve connector so that it covers the braided leads of the two wires.
Heat the solder sleeve connector with the heat gun to melt the solder and sealant inside the solder sleeve connector onto the braided leads, ensuring a strong connection.
Plug the replacement headlight wiring harness that was just soldered onto the vehicle's headlight circuit into the rear of the headlight assembly.
