Hi, the central locking works fine apart from one rear door which sometimes locks,  usually doesn't!

Do I have to remove the door card ( if that's what it's called) and is it easy? Thankyou 

2 hours ago, Wesdave said:

Do I have to remove the door card ( if that's what it's called)

Recent studies have shown that in 100% of cases the use of telepathy has failed 🙁 and the door card (yes that is the correct name) has had to be physically removed.

2 hours ago, Wesdave said:

and is it easy?

Fairly easy, should only take 10 minutes. The use of some plastic trim tools help and/or large flat blade screwdrivers. 👍

 

Hi I had the same problem with one of my back doors not locking.i purchased a new lock though it would be a simple change over turns out nearly everything  on the door needs to be removed including the glass just to change the lock.it was beyond me so I supplied lock and let garage fit it.was problem sorted.

Thankyou both, I don't have the patience any more for tasks such as this, I don't have a garage to work on it in either ,

I'll ring my  local garage and get a quote, cheers, Dave 

Just a thought. Had a problem of rear door not unlocking and also front passenger door. In both cases charging the battery fixed it! Fiesta low battery charge seems to randomly shut down things.

Thankyou, I'll check that although even after a good run it's still rarely locks, cheers, Dave 

9 minutes ago, Wesdave said:

I'll check that although even after a good run it's still rarely locks,

Point to note:

Modern car charging systems do not work like they did in the days of the Cortina. They use a 'smart charge' system (some would say dumb) which mostly only charges the battery on the engine overrun, that is when the engine is slowing down. As I frequently say, "you could drive to the moon and back and the best you could hope for is a battery charged to 80% "

I'm not saying whether or not the problem of the locking is or is not related to the State Of Charge (SOC) of the battery, only that you shouldn't assume it is well charged just because its had a good run out.

Thankyou, I'll check that although even after a good run it's still rarely locks, cheers, Dave 

I didn't know that, what a weird system! I'll definitely give it a charge once this rain blows over, thankyou 

1 minute ago, Wesdave said:

I'll definitely give it a charge once this rain blows over,

Please ensure that the charger negative lead is connected to the vehicle chassis earth point and NOT to the battery negative terminal.

I will but may I ask why? Is it s foible of modern cars ?

8 minutes ago, Wesdave said:

I will but may I ask why? Is it s foible of modern cars ?

The quick answer is "To Save The Planet" 🤣

The longer answer is, it allegedly reduces the emissions by reducing the alternator load on the engine while driving, and using the alternators drag to slow the engine on the overrun and make use of the waste energy.

Car's that do lots of town driving often have batteries with a better SOC than ones that do a 10 mile trip on a motorway.

Also to reduce emissions the cars charging system is set at the factory to only charge the battery to a maximum of 80%. This means that when you have to charge the battery from the mains those emissions don't count towards the vehicles emissions 🤔

The car uses a Battery Monitor System (BMS) to keep a check on the SOC. The sensor is mounted in the negative battery lead, which is why you must connect the battery charger lead to the chassis earth point. This means the sensor can monitor the charge going in to the battery.

17 minutes ago, unofix said:

Car's that do lots of town driving often have batteries with a better SOC than ones that do a 10 mile trip on a motorway.

I'm starting to think this is the explanation for the start/stop behaviour I mentioned in this (now quite long) thread: https://www.fordownersclub.com/forums/topic/115331-car-battery-mk8/

Briefly - S/S went AWOL last summer and mysteriously returned this February. I've always tried to avoid doing short journeys but circumstances meant I was having to do so, and I noticed that S/S (and other stuff, such as interior and boot lights) had started working again. 

I still do longer runs of course, but don't now bother too much if I end up popping to the shops (or whatever) several times in a day. Hey presto - everything works!

So it seems the "answer" -  if there's one - is hitting a mix of driving that the system seems to like.

Great explanation, thankyou