Locking problems of an electical nature?

[AlanS]

This one should have your thinking caps working overtime.

A few weeks back, I get out of the 16V and press the key fob button and nothing happens. Easy fix thinks I so I get a new battery for the fob. Still no go. Ah ha, loks like something's amiss with the alarm I think.

A few days later as I turn the key from off - accessories - on, there is a short sound comes from all the door locks as though the central locking is trying to activate but no doors lock. Each time I stop and then turn the switch from off to on this noise is made for a split second but the doors don't lock; just sound like they're about to.
A couple of more days pass and I go to get some petrol and have a clown at the bowsers whio is one of these who likes to examine the bowser, wash the screen, admire the scenery and then after remembering he's forgot his wallet and returning to the end of the queue returns to his car and proceeds to read the paper before taking off, so I turn the engine off. As I go to restart, again it goes 'wheeee' as if it was going to lock as per usual, but then the starter struggles to start it. A few days later, the battery goes flat. I recharge and it dies again the following day, so I remove from the car and recharge and leave it for 2 days and it turns out the battery's stuffed. Fit another battery (unknown condition) and it also goes flat in 24 hours, so I have bought a new one to put in later today.
If I get the locking knob on the door and push it up and down a few times and then hit the key, the noise usually disappears for that one start, but stop agion in 2 minutes and hit the key and sure enough.....it's baaaack.
The key fob still no goes, yet if I use the key itself to manually lock the doors, the central locking works as it should.

Anybody got any ideas?

It's fitted with a Mongoose Alarm which were fitted by the importers on cars brought over here I understand.


Alan S

[tom]

Well, I would take the fuses out of the mongoose first to see if it all works properly and then look across the relay contacts on the locking black box with my meter set to beep continuity if it didn't. That would tell me if the signal was getting from the plip receiver. If it is, then discount that. It works.
Now that it is getting a little deeper, I'd disconnect the motor on the driver's door and see if it works. No? do the same with the passenger's door and replace that of the driver's. My guess is that one of the switches has gone awry but logically I would rule out the alarm interlock first.

[AlanS]

Tom,

The "black box" for the locking....where is it located?
Is it in the centre console?


Alan S

[tom]

Yep. Beside the handbrake. it uses eight of the nine pins on the connector and you'll find it very easy to fault find. I'll try and put my electrical manual onto a memstick and Email it to you because I wrote quite a long chapter on debugging this bit Expect something by Monday and if the weekend's BX and CX rescue missions have chased it out of my head, PM me to wake me up.

[AlanS]

Thanks Tom, I look forward to it.


Alan S

[AlanS]

OK, here's an update to try out all those electrical specialists who reckon they've seen everything; if they haven't, they will have by the time they work this out.

I didn't get a chance to go searching for the locking problem as I was also doing a cambelt change at the time.
When completed, I soted the air/con, then managed to stuff the harmonic balance, and then the battery decided to die.

Buy a new $168 battery suitable for "European cars" and fit and begin a series of test drives as I gloat at everybody for having the coldest air/con they've ever seen in a 16V.
Suddenly it dawns on me; the self locking noise has gone. Next I notice that the clock that used to have parts of the digits missing, is suddenly complete again and finally, the in car phone kit I use for my geriatric mobile that used to be always showing it was charging yet the battery would be flat within 24 hours even with no use, is suddenly fully charging the phone battery.
So is it coincidence? Was the previous battery holding a surface charge that broke down when under load? Could it have been a strange fault with the battery such as one plate being in assaboutface? Is the car haunted???
Anybody want to advance some theories?



Alan S

[kiwi]

Batteries do some weird things when they are in that stage of no return.

A couple of nights ago on one of those unusual for me night journeys I noticed my headlights kept dimming on and off. The cause was the Automatic window closer switch trying to close a already closed window. Tap on the manual closure fault cured I was starting to think battery.

Last October my trusty little Ponty Lemans Auto a week or so before I got the BX started to be a none starter up on the mountain. Strange thing is it always started down lower and at home, never had any problems taking it to town until over Christmas (typical) the car would not hold a charge in its battery. The colder climate and altitude were the early signs of battery decay that eventually reached a point of failure in normal conditions.

I have this sneeking feeling that the BX battery will not last much into the winter either. well its 4 years old judging by the markings as well

[tom]

Ya know those big black connector blocks from the positive of the battery?
They're waiting to see you and your wire brush.

[AlanS]

First place I went when the car began to play up. Clean as a whistle and I always refit with the added security of a large zip tie after I had one go yaya on a CX one dark night which culminated with me almost disappearing off a cliff on top of a mountain when the entire system suddenly went dead.
Thanks for the thoughts just the same.


Alan S