I finally decided to remove the ancient Cobra alarm (couldn't find any reference to it on the net, not prepared to take it to Cobra for a day for reprogramming/troubleshooting) so I took it out. I had long since disconnected it from the green immobiliser wires so I just had to blank off things like power, ground, horn etc. The only connection I found to the central locking unit was one wire than when grounded causes the system to lock, and one that when grounded causes the system to unlock. Those I just insulated and tucked away neatly.
Before then everything worked right, all doors opening or locking with a partial turn of passenger or driver side key, unless deadlock was engaged.
Now, the driver's door locks all doors and unlocks them when the lock is switched from unlocked to deadlock position - except when it seems to have trouble activating the other solenoids which can make a buzz (stall) noise for a short time. Passenger door doesn't unlock any more (of course, since the system is now either unlocked or deadlocked). I can live with it this way but I'd rather it worked as designed.
Any clues? What is the typical interaction between a car alarm and central locking?
Central locking gone from fully working to half-working
Moderator: martauto
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Brianmoooore
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Does the system work properly if you briefly earth the two wires you disconnected from the alarm?
Have you been locking the doors with the key for some time, or using the now disconnected alarm?
Have you been locking the doors with the key for some time, or using the now disconnected alarm?
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Brianmoooore
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The alarm fitters strike again, with yet another butchered loom, by the sound of things! All alarm connections are provided by BMW in the vicinity of the glovebox area. There shouldn't be anything connected on the driver's side.
Chances are that you've disturbed a corroded driver's door plug and socket, and will need to perform the well documented 'red/black wire modification', but check earthing the lock/unlock request wires first.
Chances are that you've disturbed a corroded driver's door plug and socket, and will need to perform the well documented 'red/black wire modification', but check earthing the lock/unlock request wires first.
(since this is a RHD car I guess the alarm connections are all around the steering column near the ECU.)
Yep, it was the alarm fitters. I looked inside the RH front door pillar armed with the wiring diagram and looked for the gn/blu, yl/blu wires that are supposed to make the control unit lock/unlock. Sure enough the alarm installers had spliced in their own wires to those inputs and run them off to somewhere else, I didn't trace them all the way. Perhaps the alarm worked as active high rather than active low? But once disconnected, everything works! And for the icing on the cake my keyless entry kit took 5 minutes to wire in after that was done - the first time I tried to add it the fuse just kept blowing.
This keyless entry kit is a "Steelmate", probably unknown by that name outside Australia but made in vast quantities in China. It was also active high and designed to completely replace the factory system. I made it active low by disconnecting the relay contacts from the circuit board and connecting one end of the normally open contact set to earth while the others went to the factory control unit's lock/unlock inputs. Sits nicely where the old alarm used to.
Now I'm very much aware that keyless entry has some disadvantages when it's not factory - if you mistakenly unlock it won't lock again after no door is opened, it doesn't flash indicators etc., won't turn on interior lights etc. So I may take it out. But it's great to know everything is now working in a deterministic fashion again.
Once again thanks for the support Brianmoooore.
Yep, it was the alarm fitters. I looked inside the RH front door pillar armed with the wiring diagram and looked for the gn/blu, yl/blu wires that are supposed to make the control unit lock/unlock. Sure enough the alarm installers had spliced in their own wires to those inputs and run them off to somewhere else, I didn't trace them all the way. Perhaps the alarm worked as active high rather than active low? But once disconnected, everything works! And for the icing on the cake my keyless entry kit took 5 minutes to wire in after that was done - the first time I tried to add it the fuse just kept blowing.
This keyless entry kit is a "Steelmate", probably unknown by that name outside Australia but made in vast quantities in China. It was also active high and designed to completely replace the factory system. I made it active low by disconnecting the relay contacts from the circuit board and connecting one end of the normally open contact set to earth while the others went to the factory control unit's lock/unlock inputs. Sits nicely where the old alarm used to.
Now I'm very much aware that keyless entry has some disadvantages when it's not factory - if you mistakenly unlock it won't lock again after no door is opened, it doesn't flash indicators etc., won't turn on interior lights etc. So I may take it out. But it's great to know everything is now working in a deterministic fashion again.
Once again thanks for the support Brianmoooore.
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Brianmoooore
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- Joined: Mon Jan 10, 2005 11:00 pm
You assume wrongly! All the alarm connections are provided behind the glovebox on the left hand side.aeberbach wrote:(since this is a RHD car I guess the alarm connections are all around the steering column near the ECU.)
An aftermarket keyless entry system would normally flash the indicators or sidelights, and can be arranged to turn on the interior lights with some minor additions.