Alarm going off during the night

David Aiketgate wrote: There are at least 4 earth wires in that loom if I recall correctly, so that your alarm wire could find an earth in that area of loom without the switch being involved.

Thanks David – yes, it’s hard to think of another explanation for the boot warning light coming on, as there seems to be nothing wrong with the “switch” in the boot latch. It’s supposed to be a good day today, so I’m hoping to get a look at the loom later.

Of course… I used to fix computers for a living, and enjoyed a very methodical approach to fault finding. The most annoying thing I discovered, early in my career, was that sometimes – maybe not often, but sometimes – two faults existed simultaneously. So you’d apply a fix to one, but the problem remained – so you'd undo that fix, for clarity, eventually find the other one, fix it, and still have the problem.

That doesn't apply to things like broken wires, malfunctioning switches etc of course – if they’re broken they need to be fixed, whatever. But I just have this suspicion that I’ll have a door switch problem too…

One thing at a time though. Is there a guide anywhere how to remove the door lock?

Thanks again
Roger

https://www.the-t-bar.com/forum/54-how-tos/92793-how-to-change-a-door-lock-mechanism

David Aiketgate wrote: https://www.the-t-bar.com/forum/54-how-tos/92793-how-to-change-a-door-lock-mechanism

What’s the matter with me? I went through the big long list carefully and didn’t spot that one. And I haven't had a drink in 11 years… sigh. Thanks

Right, update – these wires look in perfect condition to me.



I mean, the car has only 14,000 on the clock, so I’d have been surprised if they’d been wrecked, but of course it had to be checked. And as previously discussed, theoretically they could be bust inside, but that shouldn't cause a short. Also, I opened the boot to turn the dash light on, and wrenched this part of the loom in every direction, with not a flicker.

One slight possibility… when I first took the switch out of the boot, the copper strip thingy looked at an odd angle – I kind of fiddled with it a bit, thinking at that stage it was only a spring of some kind, and it didn’t look right. It’s just possible, I suppose, that it was making intermittent contact with something, and I’ve bent it into the correct shape now… anyway, I’ve had a good play with it and it seems to be switching perfectly. Only time will tell.

But I think this does rather point to one of the door switches, as Roverlike has said :rant:

Time to read that guide…

It's OK You're not going blind. That 'how to' had slipped the net and wasn't in the lists, until I found it and put it in just now! I knew we had one somewhere 😀

David Aiketgate wrote: It's OK You're not going blind.

Who said that???



Having looked at the guide, it reminds me of when I tried to do a similar job on my Rover 75, ended up with bits all down inside the door, broken clips etc, so it might be time to take it my man (who also has a T4 etc).

I love to fix things myself, but as I get older, I've started to accept my limitations more...

PS as it seems this is a common fault on TFs, if I buy a 2nd hand lock, is there not a fair chance it will be faulty too, or will go that way in the near future...?

Actually... I'm getting ahead of myself anyway, aren't I. Somebody said earlier in this thread that I could disconnect the door switches... see what happens first.

How hard is it to do that?

Hogweed wrote:
PS as it seems this is a common fault on TFs, if I buy a 2nd hand lock, is there not a fair chance it will be faulty too, or will go that way in the near future...?

That is true. It is a game of numbers and luck ...

Roverlike wrote: That is true. It is a game of numbers and luck ...

Oh great. As Basil Fawlty said “I’m so happy.”

Does this micro-switch also operate the internal light when the door opens…?

In other words, do I need it at all…:dry:

OK, modified approach… I took the car out today for a good thrash, couple of hours, fast, slow, stop, start, open the boot/close it again, over bumpy roads etc, and no sign of the boot warning light coming on, so I cautiously suspect my diagnosis of a bent spring contact in the boot lock, which I absent-mindedly straightened again, was the cause of the warning light coming on.

However, during the period when I isolated the switch completely, the alarm still went off once, so I suspect two problems. The car only has 14000 miles on it, so I’m going to take the view at this stage that the volumetric sensors are more likely to be responsible than the door switches – so will lock it with the key every night, and pray for the neighbours.

Just one thing… where are these sensors? Can’t spot them anywhere…

Hogweed wrote:
Oh great. As Basil Fawlty said “I’m so happy.”

I am glad you are happy

Hogweed wrote: Does this micro-switch also operate the internal light when the door opens…?

In other words, do I need it at all…:dry:

Yes, these switches operate internal light when the door opens. If you want to isolate them, I can provide you info which pins you would need to isolate from door lock connector. However, in that case internal lights will never be on with door opening, and alarm will assume doors are always closed.

Hogweed wrote: OK, modified approach… I took the car out today for a good thrash, couple of hours, fast, slow, stop, start, open the boot/close it again, over bumpy roads etc, and no sign of the boot warning light coming on, so I cautiously suspect my diagnosis of a bent spring contact in the boot lock, which I absent-mindedly straightened again, was the cause of the warning light coming on.

You well may be correct as straightening spring might do what was needed. I assumed that you fixed that problem when you described earlier what you did.

Hogweed wrote: However, during the period when I isolated the switch completely, the alarm still went off once, so I suspect two problems. The car only has 14000 miles on it, so I’m going to take the view at this stage that the volumetric sensors are more likely to be responsible than the door switches – so will lock it with the key every night, and pray for the neighbours.

I was not aware that you did not lock only by key when you were trying things. I assumed that you isolated volumetric sensor during testing pwriod. If you did not, then, as you said, I would also suggest to do so and see if that is the problem, before attempting to do anything on door side.

Hogweed wrote: Just one thing… where are these sensors? Can’t spot them anywhere…

Sensor (you have only one) cannot be seen. It is microwave sensor (not ultrasonic one) and it resides on the (under it) T-bar in the middle of two seats.

Roverlike wrote: I was not aware that you did not lock only by key when you were trying things. I assumed that you isolated volumetric sensor during testing period. If you did not, then, as you said, I would also suggest to do so and see if that is the problem, before attempting to do anything on door side.

Well, I did, yes… but I’m thinking maybe that was when the boot switch started messing about. So then I thought OK, it’s not the volumetric sensor, and started locking the car with the remote again. So now I know I’ve fixed the boot switch, I can test the volumetric one again. I know what I mean anyway! I think.

Thanks as always for the helpful pictures etc – fantastic.

Ummm… that little connector… so can I just disconnect the microwave sensor with that?