Having wasted my entire day it seems unlocking by the passenger door has done the trick! Having said that, I'm reluctant to lock the car any more in case I get more problems. The 'door open' warning light, which had flickered previously, is now on all the time (after my WD40 effort on the bonnet switch. The car doesn't really need to be locked most of the time anyway. Any more advice?
Hello again. As the passenger door lock switch works you can lock it and just remember to unlock on the passenger side door but I would replace the driver's switch before you have any more problems. If the door ajar warning is on due to the bonnet switch and it is staying on this should stop the alarm arming anyway but obviously as there is a problem with the switch you may end up with false alarms. Below is a link to show you the type of switch I'm referring to. http://www.ebay.co.uk/itm/Ford-Fiesta-MK3-New-Genuine-Ford-Door-lock-alarm-switch-/281265380233?pt=LH_DefaultDomain_3&hash=item417cb91b89
Let me know if I can advise further. Best wishes, Sean.