andy, it sounds very much like the relay has gone, as you say, you have checked the motor and the switch. warning!! orange cabling is only used on the airbag system, this is a european directive to enable easy identification for the rescue services to disable the system without the bags deploying whilst attempting a rescue, or serious injury could result,check to see if they are missing from your steering wheel airbag,they might have been disconnected for a reason!! paul
Relay seems to be working as I get 12v at the motor when ignition in position 2. Could the hazard warning lights be a clue as they are not working either