An integrated manifold assembly (500) for routing electrical signals in an internal combustion engine is disclosed. The assembly includes an air-intake manifold (506) for drawing fresh air into the internal combustion engine, a main circuit portion (508) fixable to the air-intake manifold (506) of the internal combustion engine, a plurality of circuit runner portions (510) extending from the main circuit portion (508) for interconnecting the main circuit portion (508) with a plurality of engine components (512, 514), and a heat sink (517) affixed to the air-intake manifold (506) and in contact with at least one of the a main circuit portion (508) and the plurality of circuit runner portions (510) for dissipating heat generated in the circuit portions.