I just replaced cam sensor in my Holden Vectra 1997 2.0L. I accidentally damaged the plug when I replaced the cam sensor. I ordered the plug (3 pin) and just arrived yesterday. The connector has 4 wires, the first one is red/gray, the second one is brown/gray and the last one is black/gray. The other one does not have any colour. Need assistance of where the wires go into the plug (pin 1?, pin 2?, pin 3?), what about the other wire? Please advise