An E28 wiring question.

In article >,
R. Mark Clayton > wrote:
> "Dave Plowman (News)" > wrote in message
> ...
> > I'm sending an alarm unit to my brother who lives some way away - and
> > all he needs it for is to provide remote lock and unlock for his '87
> > 520 which doesn't have it.

> I can just about understand the remote unlock (if you have salvaged it
> for nothing from another car being scrapped),

Yes - that's all it's for. And it came off my 'other' 25 year old car. To
which I've fitted a more sophisticated one. ;-)

> but an alarm for a 22 year old car worth little more than its scrap
> value unless it is in absolutely concours condition...

True - but older cars are often targeted by joyriders etc since they have
little or no security. This alarm does have an immobiliser circuit if
needed. And although it may have little value having a car stolen is
inconvenient to say the least.

--
Is the hardness of the butter proportional to the softness of the bread?*

Dave Plowman London SW
To e-mail, change noise into sound.

"Dave Plowman (News)" > wrote in message
...
> In article >,
> R. Mark Clayton > wrote:
>> "Dave Plowman (News)" > wrote in message
>> ...
>> > I'm sending an alarm unit to my brother who lives some way away - and
>> > all he needs it for is to provide remote lock and unlock for his '87
>> > 520 which doesn't have it.
>
>> I can just about understand the remote unlock (if you have salvaged it
>> for nothing from another car being scrapped),
>
> Yes - that's all it's for. And it came off my 'other' 25 year old car. To
> which I've fitted a more sophisticated one. ;-)
>
>> but an alarm for a 22 year old car worth little more than its scrap
>> value unless it is in absolutely concours condition...
>
> True - but older cars are often targeted by joyriders etc since they have
> little or no security. This alarm does have an immobiliser circuit if
> needed. And although it may have little value having a car stolen is
> inconvenient to say the least.
>

Don't forget, Dave, the ignition bypass that gets activated by locking the
doors. You want to be sure that the device you are installing will enable
the Ignition Bypass.

I wish I could help you more, but I'm struggling with a Trunk Lock Switch
that won't unlock the doors, but will lock them. I discovered that if I turn
the car OFF and climb out with opening the doors, then the trunk lock will
lock the doors, but the Ignition Bypass is disabled -- somebody could get
into the car and it will start.

In article >,
Jeff Strickland > wrote:
> > True - but older cars are often targeted by joyriders etc since they
> > have little or no security. This alarm does have an immobiliser
> > circuit if needed. And although it may have little value having a car
> > stolen is inconvenient to say the least.
> >

> Don't forget, Dave, the ignition bypass that gets activated by locking
> the doors. You want to be sure that the device you are installing will
> enable the Ignition Bypass.

As I said all it will do is replicate the action of manually operating the
boot lock. Nothing more, nothing less. So will have no effect on anything
else.

> I wish I could help you more, but I'm struggling with a Trunk Lock
> Switch that won't unlock the doors, but will lock them. I discovered
> that if I turn the car OFF and climb out with opening the doors, then
> the trunk lock will lock the doors, but the Ignition Bypass is disabled
> -- somebody could get into the car and it will start.

The central locking has some form of controller - as obviously holding a
key in the locked position would continually apply power to the motors. So
in its most basic form consists of a timer which cuts off the signal from
the switch after about 1 second. But it can also provide other functions
like setting and disabling any immobiliser, etc. My guess would be that -
or the connectors to it - is the problem. If you have a wiring diagram for
the car it should be possible to trace what it's hooked up to as well as
just the locking.
However, my E39 has a very different boot lock mechanism to the E28. The
central locking motor is spring loaded so returns to a rest position after
operating. This is to allow the boot to be actually opened by the press of
a button rather than just unlocked. There is a 'prove' microswitch inside
the motor to tell things it has returned to rest. But I dunno the full
logic of what does what on this system.

--
*Constipated People Don't Give A Crap*

Dave Plowman London SW
To e-mail, change noise into sound.

"Dave Plowman (News)" > wrote in message
...
> In article >,
> Jeff Strickland > wrote:
>> > True - but older cars are often targeted by joyriders etc since they
>> > have little or no security. This alarm does have an immobiliser
>> > circuit if needed. And although it may have little value having a car
>> > stolen is inconvenient to say the least.
>> >
>
>> Don't forget, Dave, the ignition bypass that gets activated by locking
>> the doors. You want to be sure that the device you are installing will
>> enable the Ignition Bypass.
>
> As I said all it will do is replicate the action of manually operating the
> boot lock. Nothing more, nothing less. So will have no effect on anything
> else.
>
>> I wish I could help you more, but I'm struggling with a Trunk Lock
>> Switch that won't unlock the doors, but will lock them. I discovered
>> that if I turn the car OFF and climb out with opening the doors, then
>> the trunk lock will lock the doors, but the Ignition Bypass is disabled
>> -- somebody could get into the car and it will start.
>
> The central locking has some form of controller - as obviously holding a
> key in the locked position would continually apply power to the motors. So
> in its most basic form consists of a timer which cuts off the signal from
> the switch after about 1 second. But it can also provide other functions
> like setting and disabling any immobiliser, etc. My guess would be that -
> or the connectors to it - is the problem. If you have a wiring diagram for
> the car it should be possible to trace what it's hooked up to as well as
> just the locking.
> However, my E39 has a very different boot lock mechanism to the E28. The
> central locking motor is spring loaded so returns to a rest position after
> operating. This is to allow the boot to be actually opened by the press of
> a button rather than just unlocked. There is a 'prove' microswitch inside
> the motor to tell things it has returned to rest. But I dunno the full
> logic of what does what on this system.
>


I had some trouble with the driver door lock a few years ago. This car and
the one it replaced would not unlock the doors from the trunk, but both of
them have always locked the doors without any complaints. Anyhow, I removed
the lock from this car -- '94 325 convertible -- and recovered whatever
functionality I was looking to recover, and when I put it back in, I think I
got something wrong with the linkage. To fix it, I have to open the door
again and I've not bee excited at the idea of doing that.

What happens now is that the push-button on the door locks, and pops up when
the inside lever is pulled, and it pops up when the passenger door lock is
turned to unlock the doors, but it does not pop up when the driver lock is
turned. I can come up to the locked car and use the key in the driver door,
and the doors all unlock properly, except that the driver button does not
come up.

I suspect I might have a problem with the proper alignment of the mechanism
that is causing a switch to be set when it ought to be free. Having said
that, I have to wonder why the passenger lock would unlock the trunk and
driver door, the driver door unlocks the trunk and passenger door, but the
trunk lock does not unlock anything but the trunk.

If I operate the ignition from ON to OFF, then remove the key -- or use a
different key -- but do not open and close the door, then the driver door
button goes up and down from any of the lock locations, but the ignition
bypass featurte is defeated -- the car can be started while the doors are
locked. If I operate the passenger door lock with the key, the driver door
button goes up and down properly. This is all so confusing ...

In article >,
Jeff Strickland > wrote:
> I suspect I might have a problem with the proper alignment of the
> mechanism that is causing a switch to be set when it ought to be free.
> Having said that, I have to wonder why the passenger lock would unlock
> the trunk and driver door, the driver door unlocks the trunk and
> passenger door, but the trunk lock does not unlock anything but the
> trunk.

If it's like the E34 diagram I have, the control circuits from the three
key switches aren't in parallel as you might expect. The door ones are -
but the boot one is separately connected to the controller.

--
*If you remember the '60s, you weren't really there

Dave Plowman London SW
To e-mail, change noise into sound.

Dave Plowman (News) wrote:
> I'm sending an alarm unit to my brother who lives some way away - and all
> he needs it for is to provide remote lock and unlock for his '87 520 which
> doesn't have it.
>
> I'd like to give him chapter and verse on the connections and set the
> alarm up correctly. But I don't have a wiring diagram for an E28 - but do
> for an E34.
>
> My idea is to fit the unit in the boot. And connect to the boot key
> switch which operates the central locking. According to my E34 diagram the
> key switch grounds either of the control wires which are coloured
> green/black (lock) yellow/black unlock.
>
> And take the power for the unit from the boot light feed.
>
> Any gotchas I've missed?

I installed remote locking on my '92 535 yesterday. Following the advise
in this thread I mounted the box in the trunk and connected it to the
trunk lock switch wires. However, grounding the control wires only
accomplished blowing a fuse. It turned out it needs positive voltage,
which is also confirmed looking at the wire diagram, to operate.

The downside with the trunk location is that you can't close the windows
and sun roof with the fob, and the "lock block" function doesn't work
either.

Either way, I'm happy. Saves me the hassle of locking the doors manually
anyways... :-)

>
Ulf

In article >,
Ulf > wrote:
> Dave Plowman (News) wrote:
> > I'm sending an alarm unit to my brother who lives some way away - and
> > all he needs it for is to provide remote lock and unlock for his '87
> > 520 which doesn't have it.
> >
> > I'd like to give him chapter and verse on the connections and set the
> > alarm up correctly. But I don't have a wiring diagram for an E28 - but
> > do for an E34.
> >
> > My idea is to fit the unit in the boot. And connect to the boot key
> > switch which operates the central locking. According to my E34 diagram
> > the key switch grounds either of the control wires which are coloured
> > green/black (lock) yellow/black unlock.
> >
> > And take the power for the unit from the boot light feed.
> >
> > Any gotchas I've missed?

> I installed remote locking on my '92 535 yesterday. Following the advise
> in this thread I mounted the box in the trunk and connected it to the
> trunk lock switch wires. However, grounding the control wires only
> accomplished blowing a fuse. It turned out it needs positive voltage,
> which is also confirmed looking at the wire diagram, to operate.

Interesting. My wiring diagram (Haynes) doesn't show the presence of a
positive feed to the motor/switch - only a ground. But I'll pass that on
to my brother.

> The downside with the trunk location is that you can't close the windows
> and sun roof with the fob, and the "lock block" function doesn't work
> either.

No such modern nonsense on his E28. ;-)

> Either way, I'm happy. Saves me the hassle of locking the doors manually
> anyways... :-)

He's replaced broken locks with secondhand ones so has too many keys.

> >
> Ulf

--
*Give me ambiguity or give me something else.

Dave Plowman London SW
To e-mail, change noise into sound.