It will be a broken wire from the ecu to the relay. If you look under the bonnet, right along the top of the engine there is a fluted plastic wiring harnes. Open it up and check the wires in there, they rub on the flutes and eventually corrode and snap. Have a look for a thin black and white wire this is the control for the relay and the chances are its broken around the right hand side of the engine somewhere. :ILU:
I've seen so many damaged wires there now
Let me know how you get on.