I think, I understand why one fuse has a duel purpose,it's just not in that configuration. The 04 manual, 8W-10 pg.20,21 shows the engine control relay and the air pump relay begin tied together. Its showing engine control fuse 1an 2. 2 being tied together to the air pump relay. Testing across the fuses ,all are hot ,except 3 and 5, then when you turn the ignition on, they are energized together....