Painless GM Fuel Injection Wiring Harnesses | JEGS Painless Performance GM Fuel Injection Wiring Harnesses make a tough job easy. They are designed to be a direct fit with the factory engine control unit. All kits include straightforward instructions and TXL high-temperature, color-coded, and labeled wire for ease of installation. Painless Wiring | SSW | Standalone GM Wire Harness | LS Painless Wiring and Speed Scene Wiring are manufacturers of engine wiring for late model Vortec GM LS1 – LS2 – LS3 – LS7 – LS9 wire harnesses. The beauty of the painless wiring harness is the fast delivery of the product, due to a mass-scale wire harness assembly line, painless wiring has deployed in there wire harness manufacturing plant.