Hi all. Randomly began experiencing central locking issues on mk 5, 2007 Fiesta a few weeks ago. Doors either wouldn't open or would just randomly lock themselves. As you pushed the handles in to lock yourself in they would just pop straight back out. Struggled getting it unlocked with the fob, and even using the key it was as if the car was trying to lock itself even as you were trying to unlock it, not sure if the term for that is 'cycling'? Felt very close to getting locked out of it due to this, even using the key. A couple of times I left it unlocked only to go back to it 5 minutes later and find it had locked itself. Garage took a look and said they thought I needed a new latch and suggested a second hand one due to the age of the car. Don't think they picked up on anything electrical. Fitted that for me, but it was still not right. You sometimes had to close the door 3 or 4 times to get it to lock, from the in or outside. Wasn't doing the random 'cycling' business at first, just had problems getting it to actually lock.

It has gradually got worse again over the last week and is basically doing exactly what it was doing before, including the random cycling thing as you try and unlock it. Sometimes I've opened the drivers door to get out and heard the mechanism inside already trying to do something, before I've even closed it. On one occasion when I set off the red light came on inside that tells you a door is still open, that went off when I stopped and checked the doors and boot were closed. Once the same red light came on when I pressed the button to put my drivers window down. I opened and closed the drivers door and this went off straight away, but this has only happened once so far.

Could it be the second hand latch that is the issue, or given that I'm back to square one, does the issue possibly lay elsewhere? Wiring or electrics? Will have to have it back to a garage to take another look, but in the meantime I would appreciate any advice as the issue hasn't been solved at all. Thanks in advance. 

The sensors in the latch go down, so the latch doesn't know what position it is in.

A new latch would solve it, but you could try completely stripping the latch mechanism down and cleaning then re-lubricating it with white grease and see if it cures it

Thanks for your response. The garage who fitted the second hand part said that they had lubricated it as I think it was playing up a bit when they did it, but it has just got worse and worse again. Do you think a brand new latch would solve it? Am struggling to get it unlocked at times, even with the key, and am concerned about getting locked out completely.

16 hours ago, jaysim said:

Thanks for your response. The garage who fitted the second hand part said that they had lubricated it as I think it was playing up a bit when they did it, but it has just got worse and worse again. Do you think a brand new latch would solve it? Am struggling to get it unlocked at times, even with the key, and am concerned about getting locked out completely.

I mean take it out and lubricate the mechanism inside, try that first

3 hours ago, DaveT70 said:

I mean take it out and lubricate the mechanism inside, try that first

Worth a try. Does it sound more like a latch issue than faulty wiring somewhere?

Thanks again for your advice. Much appreciated

Possibly latch

Clean everything and lubricate and see how you get on from there