I have a 1993 Explorer 4X4. The 4WD stopped working so I bought a new actuator from NAPA. This actuator did not have the same number of wires as the old one. It was missing the red and the blue/brown wires. I installed it anyway and now the 4WD works but only in high range. Low range is not working. Do I have the wrong actuator or is there a further problem with the transmission?