Locked out and will not start - alarm sounds off

Delbourt wrote:

Regarding the origin of the wiring sketch. Yes, that seems to ring a bell in the memory.
Hopefully someone (perhaps Roverlike or anyone else) well versed in the electronics of these cars can add some further explanation regarding the issues Im experiencing with these locks.
Im very puzzled why the manual key could not overwhelm the system with or without the battery connected, but thankfully once the battery charger was connected and that presumably boosted voltage the fob operated the system.

 

I wrote you the 2 answers on your 2 questions, but seems to me that you did not read that answer as you just kep posting questions.

Regarding the key not overriding things, you need to be aware that your door lock is one part with actuator and they cannot be separated (like in case of Rover 600). Key is just one way of communicating with actuator, while actuator drives everyrhing else. So your door lock is fully electric and key is just part of that. It cannot work alone. That is the way how MG-Rover designed it.

Thank you for the reply. You are confirming that with the battery connected as normal there is no manual override. Correct?

When I had one of these locks dismantled into it’s component parts and re assembled on my workbench (without the closing cover in place) but operated such that super lock was activated manually by rotating the gear wheels it was perfectly possible to release the lock by operating the key lever.

So if the battery is disconnected it should be possible to use the key and open the lock. But that wasn’t possible.
So I need to establish why not please.
With no electrical power supplied a mechanical force should overcome the system.

Actualy it is the oposite then you said. 

As far as I know, in case of Lucas 5AS alarm which you have, superlock cannot be invoked by key, it must be invoked by fob. For that you need electricity, so you need battery connected. If you use key, you should be able to open the superlocked door, because key turned to unlock should invoke electrical signal for superlock to disable as well.

If there is no electricity, superlock disable signal cannot be sent to door lock and you cannot unlock superlocked door. 

You can unlock the door by the key without electricity only if it is not superlocked because levers and mechanics in the door allow that.

If I am not mistaken, with superlock engaged particular lever in lock is positioned far enough that other mechanical parts cannot reach it.
 

Thank you for confirming the operation. If I suggested that the key operation would engage super lock that is not what I meant. I use the key to lock the car to ensure that both the “volume sensor (?) ” and super lock are not engaged deliberately or accidentally.

When I had the lock dismantled down to component parts some months ago I agree that the additional movement of the quadrant positioned the rest of the opening features inactive. I am quite sure that movement of the lever attached to the rod associated with the “key” released super lock.

I don’t have the time to repeat that test at the moment but will do so in a week or so all being well. When I have repeated the test I will post my findings on here.

In the interim and assuming that Im right for the moment Im at a loss as to how to explain why the key didn’t work yesterday. My only thought being that the battery was still connected and “the system” was resisting the key movement.
Ill try it with the battery disconnected (the alarm horn has been disconnected at the moment to keep the neighbours happy).

My question about battery voltage and disconnect etc was more to do with seeking an answer as to why on a cold night with everything normal and locked by using the fob (button pressed once), and the car locked up in the garage why does the alarm sound in the middle of the night for no apparent reason. Since that time the car has been locked using the key with no repetition of the alarm sounding.

Recently I think the battery is either discharging due to a fault possibly associated with the lock operation, or failing due to age . I don’t have any reference to the battery age and its installed date is not marked on the battery.

For yesterday situation in which you could not open the door by the key, if you had resistance when you tried to move the key in unlocked position, then most probably you have some plastic part which broke inside the lock and preventing movement of the key to unlock position. If that cleaed afterwards you might be lucky that part moved from blocking position. However if that happened, I would be worried for that to happen again and not move afterwards, in which case you will not be able to open the door by the key at all.

For alarm sounding on cold day, you will know if car battery power went down so low it behaved like disconnected in a way that when you tried to silence the horn by the unlock button on the fob, it did not react on first press, but on fourth or fifth. That behaviour proves that alarm box was without power and you needed to re-sync the fob first, before you could silence the horn.

If bench test proves that you can open superlocked door by key, that would mean lever of the key is long enough and never can be put into position not to open the door - either locked or superlocked, with or without the car battery connection. 

With above assumption if you could not open the car by the key, as I said in previous post above, something might jammed the key operation. But that would warn me to inspect door lock as if that jammed once there might be another time.

Thank you for clarifying the lower temperature position.

Im beginning to suspect a failing 5AS.
The door lock mechanism that I have recently removed and the item I have replaced it with are behaving in identical fashion. Whilst not impossible I feel it unlikely.
The battery (disconnected overnight) is holding a state of charge that might not be perfect but is over 70% and 13.5 volts.
Once I reconnect the battery and try the door locks there is an initial positive response (ignoring the car horn as I have disconnected it temporarily).
The sill button goes up and down as it should, the key will lock the door audibly.
However, the mechanism doesn’t release the catch.
So more operation of the fob with much chattering from the sill button as it rises and descends rapidly for several seconds eventually delivers a position where the door opens.
This leads me to think it must be the 5AS. It’s the common part unless the passenger door is also in fault mode which I don’t believe it is.

Presumably the 5AS has a timer in it and if it doesn’t receive confirmation of an action what does it do?
If the door locks cant match that speed due to age or micro switch condition what is the answer?
Replacement micro switches of the required dimensions and pin movement do not seem to be available.

Thoughts please

What you described for me means you have failing mechanic locks and plastic gear parts are close to full jam. From my point of view 5AS is doing what is expected and from description I do not have doubts n 5AS. For me 5AS is sound and doing its job.

It would not be the first time to have 2 items faulty in same way. 

It might be a case of dimensions clash.
Yesterday I didn’t climb in through the open window but did lean in and looked. It might be a case that the arc movement of the lever operated by the key is such that the rod is prevented from descending further by the door construction and what I presume is the Side Impact Bar feature or stiffening  feature.
if that is the case it might explain why the key will not overcome super lock. Im convinced that when operating the associated lever on the bench it did. At the moment the car is now covered over in my garage whilst I concentrate on other matters.

My expertise - such as it is - does not include the finer art of electronics.so It is difficult to question the wisdom that suggests that the 5AS is not at fault. 
However, I remain convinced that “on the bench” the operation of the lever associated with the key will override the superlock. 

Here below is what I wrote a year or so ago and posted on here. And I am therefore firmly convinced that if the lever can be moved mechanically through sufficient arc with no battery connected the door should open. To me that is a very sensible and something I would have thought MG designers would have required. 

Here is the relevant text.
Once the cover had been removed the motors and micro switches were lifted clear and the mechanism operated several times by manually closing the latch, operating the locking button, the door handle lever(s), the key operation lever, and eventually moving the system to the superlock position. By swinging the superlock pawl out of the way it was seen to be easy to move the system to superlock and that nothing prevented the system from returning to the open position i.e. there was no need to lift the interlocking pawl clear for the system to return to the unlocked position if unlock was called for.It was seen that once the system was in the locked position the door could not be opened by use of either of the door handles as expected. In that first locked position the door button could unlock the system and the door could then be opened using either of the two door handles (again as expected). If the system is moved to the superlock position the door button became inactive i.e. it was not possible to unlock the system. However, if the key was deployed it was possible to overcome superlock and return the system to open. That would seem to be entirely sensible. It should be noted however that it was not possible whilst bench testing to move the system to the superlock position once the motors and micro switches were re fitted. So gaining a sense of how difficult it might be to move from superlock to unlock using the key only could not be assessed. As the existing lock fitted to the car will not move to superlock it has not been possible to make or confirm that assessment with a live system using the key

https://www.the-t-bar.com/forum/9-mgf-tf-pitstop/99318-defeating-superlock#210447