locks spontaneously unlocking- how to narrow down which actuator?

[EricV]

Hi all. Here's the pickle...something I've been able to live w/ until last night, when someone rifled my interior while I slept. Didn't take anything, but pulled loose the access panel to the sunroof (wtf?) and other odd interior touches.

For some time my car just unlocks itself. If I lock it they pop right back up on their own, usually right away but once I do get them to stay down, they'll pop up many hours later.

Now I have read up on this, so I understand that one of the most common causes is a sticking/resistant/malfunctioning actuator. Oh- and the trunk harness/bundle 'o wires...I did have some frayed but I think I've got them all straight.

Anyway, what I want to know is if there's any way to narrow down which actuator/area it may be- seems to me I'm looking at lots of labor intensive trial and error pulling panels and trying to narrow this down to what's causing it to go into default mode (apparently when something is amiss, these things auto unlock.)

Any ideas? Further, I thought of just pulling the fuse- but apparently it's not that simple to render manual. I'm awaiting a test on Fri to see if my head gasket is leaking, and I'm really not looking to sink a lot of money into this issue right now, but need to rely on it staying locked in light of what's happened.

Thanks for any suggestions and ideas.

Eric

[Blitzkrieg Bob]

alarm system?

Keys entry system?

Bad actuator...Listen for the one the makes a little whine or zzztt sound when you run the key from full clock - counter wise.

Worst case the trunk harness is shorting out your locks.

[Paul in NZ]

crash "sensor".Its ussually the drivers one,because only the driver(maybe passengers) commands all the other doors to unlock/lock

[EricV]

Nah, no alarm, keyless entry or any of that. '93 525 w/ simple central locking.

I'll look again (more closely) at the trunk harness, and also do a search on the crash sensor to see what I can learn about that.

If anyone else has input that's great also.

Thanks!

Eric

[EricV]

Tell me this, please...

A couple of years ago I attacked the issue to no avail. B/c of where I lived then it wasn't an issue. Now it appears it is (as evidenced by my interior being half disassembled as I slept the other night...still makes me sick to think of someone in there rifling through my car and disassembling sh*t, but oh well...)

Anyway, I won't be able to attack the problem thoroughly until the weekend...is there ANY way to disable the power locks and just go manual? I tried it a few years ago, but it appeared there were too many redundancies built into the system (just that, redundancies to keep it active, and numerous fuses which control other, essential, functions.)

Thanks!

Eric

[Paul in NZ]

Tell me this, please...

A couple of years ago I attacked the issue to no avail. B/c of where I lived then it wasn't an issue. Now it appears it is (as evidenced by my interior being half disassembled as I slept the other night...still makes me sick to think of someone in there rifling through my car and disassembling sh*t, but oh well...)

Anyway, I won't be able to attack the problem thoroughly until the weekend...is there ANY way to disable the power locks and just go manual? I tried it a few years ago, but it appeared there were too many redundancies built into the system (just that, redundancies to keep it active, and numerous fuses which control other, essential, functions.)

Thanks!

Eric

pull all the fuses you want...it doesnt matter what goes out if its parked does it...of course once you pull all the fuses all the doors better be locked otherwise you will have to lock each one manually!

[sal_park]

A quick but crap bodge - unscrew all of the pull leavers* (part 6 here (http://www.realoem.com/bmw/showparts.do?model=HD52&mospid=47375&btnr=41_0815&hg=41&fg=40&hl=61)). Although this won't stop the locks unlocking, it will make it much less obvious that they are unlocked.


hth

sal



* but do keep them in the car so if you need to unlock the door from the inside for what ever reason, you can

[EricV]

Thanks Paul, but I'm afraid I must not have been clear.

It does matter. You see my goal (in the meantime, until I have time to properly diagnose/fix) was to disable the locks so I could just operate them manually and still use the car all week (without having to plug fuses back in each time to go someplace.) The issue is that b/c of so many redundancies and things coupled onto each fuse/circuit, this appears to not be possible.

I long for the good 'ol days when you could just disable the frivolties that just aren't worth fixing on such an aged car.

Thanks-

Eric

[sal_park]

Hi Eric,

ok, slightly more hassle solution - remove the door cards and unplug the connector to the lock actuator on all doors. You may want to leave them off until it's all fixed (no point taking them off/on/off/on etc)

I think (take this with a large pinch of salt - I've not taken apart my doors and this guess is based on replacing a lock actuator on an E36) but all the electical plug connectors should be mounted on this piece of plastic:
(item 17)

http://www.realoem.com/bmw/showparts.do?model=HD52&mospid=47375&btnr=41_0730&hg=41&fg=40

[sal_park]

Hi Eric,

ok, slightly more hassle solution - remove the door cards and unplug the connector to the lock actuator on all doors. You may want to leave them off until it's all fixed (no point taking them off/on/off/on etc)

I think (take this with a large pinch of salt - I've not taken apart my doors and this guess is based on replacing a lock actuator on an E36) but all the electical plug connectors should be mounted on this piece of plastic:
(item 17)

http://www.realoem.com/bmw/showparts.do?model=HD52&mospid=47375&btnr=41_0730&hg=41&fg=40


edit... handy guide via a quick google:
http://www.bmw4life.com/doorLockActuator.htm

[Tiger]

Majority of the time it is because of the cable bundle by the trunk hinge... make sure they are not frayed... pinched or broken. Tape the wire to the hinge so it doesn't get pinched again.

It recently did that to my car and that wire bundle was loose because the trunk was replaced... Since I taped it up and secured that wire bundle... no more self unlocking.

[EricV]

Sal/Tiger- thanks a lot. I'll be looking into this, hopefully after work today (weather permitting!)

[EricV]

I'd fixed the bundle a year or so ago, but have to admit I could/should go back through that thick little bundle to make sure it's held up and was thorough. At the time it didn't help, and I moved on.

After that incident a week ago I gotta do something, so I might as well take a stab at pin pointing it and fixing it (disabling isn't an easy option...might as well go the last couple yards...)

SO, please tell me this gentlemen...if all of my lock knobs go down (and then of course pop back up) at the same time (in unison) would that suggest they are working fine and I should then focus on this crash sensor or the trunk lock actuator? And of course re-visit the bundle to be sure.

Just want to hear from those w/ exp in what order they'd target before I go pulling all the door panels.

Thanks!

Eric

[632 Regal]

Eric,

I have the buttons popping thing going on for a long time and just for the heck of it pulled the cover on the hinge to inspect. I have a wire that's completely cut, purple if memory serves. My trunk lock does not make the door locks open or close so I believe that single wire is responsible.

[EricV]

Thanks fella. I'll definitely have to revisit that bundle very soon (we had a lot of rain this weekend, and unfortunately I don't have a garage...bummer.)

I'll keep you guys posted!