Reproduction of the original engine wiring harness manufactured using original General Motors schematics and specifications featuring the correct attachment connectors, wiring in the correct color and gauge sizes (when available), and OE-style terminals to match the original harness in order to maintain authenticity and proper functionality. Each harness is fully assembled, taped, and ready to install. This engine harness will plug into the firewall at the factory location and will follow the original routing in the engine compartment. A combination of the engine and front light harness will accomplish most functions under the hood of an early GM vehicle. Engine harness design varied significantly from year to year, but most will contain wiring for the ignition system, starter, heater blower, and temperature/oil pressure sender wires if applicable. Some vehicles used a capillary tube to provide an oil pressure reading, so these will not be included in a wiring harness. On vehicles with ignition points, the circuit feeding the ignition coil was designed with some resistance to extend the life of the ignition point set. Modern electronic ignition systems or high-energy ignition (HEI) systems do not require resistance in the circuit, so it is recommended that a harness modified for HEI be ordered if the ignition system has been upgraded.
