Wiring harness assembly for an intake manifold

A wiring assembly for a plastic intake manifold mounted to an internal combustion engine of a motor vehicle includes a flexible circuit assembly disposed within foam covering the intake manifold. The flexible circuit assembly provides for electrical communication between a controller and a plurality of electrical devices. In one embodiment the electrical devices are integral to the flexible circuit assembly to create a flexible circuit/electrical device assembly forming a single replaceable unit. In another embodiment, multiple flexible circuits are sandwiched between layers of foam, with each flexible circuit separated from the others by layers of foam. Each of the multiple flexible circuits attaches to different types electrical devices or sensors. The invention also provides for a decorative skin disposed over the layers of foam that may include a printed design to eliminate the need for an additional decorative engine cover.