Attatched to the battery box underneath the coolant resevoir there is three relays, two have the relay plug attached but the third one which does not have a plug. It has four wires 2 x yellow/green, purple/white, not sure of the other wire any guesses as to what the missing relay is for?

Not a lot of info to go on, but I'll guess it's the headlight circuit breaker.

Normally there are 3 relays sitting alongside it - ECU, fuel pump and WAC (air con).