Central locking query!

Wed Mar 12, 2014 7:11 pm

Hi i have a Pre-Face Cabby and I'm trying to sort out my central locking problems. I have changed the actuators in the boot and the doors and after finding out about some horrible wiring from the previous owners i have managed to correct them sort of!

Now have the central locking working when i manually use the actuators up and down which locks the boot and petrol flap. For some reason the front doors do not lock?

i am also missing both front microswitches.

Any help would be great, thanks!

Thu Mar 13, 2014 9:52 am

how do you mean to ground them, splicing them from the loom isn't ideally what i want to do?

Thu Mar 13, 2014 10:13 am

Connect a piece of wire to earth, and slide the free end into the socket for the ECU from the wire side, so as to make contact with the bare terminal.

Thu Mar 13, 2014 10:25 am

sorry i think I'm misunderstood still, the central locking ECU is the same as the central locking relay?

Thu Mar 13, 2014 10:28 am

No such thing as a central locking relay, other than as integral parts of the locking ECU, which is the rectangular black box in the sill.

Thu Mar 13, 2014 10:33 am

right it makes sense now! so open the black box and ground one of the pins there?

Thu Mar 13, 2014 10:49 am

is their a need for the microswitches also?

Thu Mar 13, 2014 1:51 pm

No need to open the ECU - just push the bared off end of the earthed wire up beside the wire in the plug.
Driver's door microswitch is only for the deadlocking feature, but the one on the passenger door supplies the lock request signal.

Mon Mar 17, 2014 7:23 pm

@Brianmoore - i still quite don't understand what to do with the grounding?

back to the central locking problem been looking at some of the wiring near the ecu area and have found this relay which is a 'Ford' Relay which is always hot? any ideas? and the toad power window module?

Mon Mar 17, 2014 7:43 pm

I've no idea what the relay in the first pic. is for. It definitely wasn't put there by BMW, and isn't the central locking ECU, which should be INSIDE the driver's side lower A pillar.
Similarly, the lower pic. is of an aftermarket window closure module. Nothing to do with BMW wiring.

Mon Mar 17, 2014 7:53 pm

right okay thanks,

i still don't understand what to ground to the central locking ECU? i have a piece of wire like you said with a bare end?

Mon Mar 17, 2014 11:59 pm

Have you found it yet?

Tue Mar 18, 2014 4:03 pm

Nope, still confused i have the central locking ecu now

Tue Mar 18, 2014 7:24 pm

willnz wrote:
Dig the ECU out from its hole behind the drivers side footwell speaker and check the following: the boot/petrol flap lock via the green/black wire and unlock via the green/violet wire by momentarily grounding either one. Do this and see if they function. then try the yellow/blue wire to lock the doors and the green/blue one to unlock them.

If the front doors do not work when you do this, bridge the yellow/blue to the green/black and momentarily ground them. If you still do not get any locking from the doors, you need to check the wiring to the actuators where they pass from the body to the door. The plug is quite prone to corrosion.

While you are at it, do the red/black conversion as well ( find the 3 red/black wires going to the door, cut them off inside the car and join all 3 together). See the WIKI for more details on this..

Wed Mar 19, 2014 7:12 pm

Today i managed to get all the actuators to unlock all the doors even the front two doors by hand when pushing the actuator up and down, however when i turn the key in drivers door it didn't unlock?

Wed Mar 19, 2014 7:22 pm

Actuator in the front door? If so, the problem is wear/excess clearance between the L shaped alloy piece on the back of the driver's lock barrel, and the steel fork it engages with.
Renewal of the alloy piece and/or careful bending of the fork is the cure, but you may realise a cure by adjusting the actuator slightly in its slotted mounts.
Should lock/unlock from the boot as well as the doors..

Wed Mar 19, 2014 7:28 pm

Yes the actuator in the front door, right ill try that tomorrow thanks!

Wed Mar 19, 2014 7:29 pm

do i need the microswitch on the drivers door if i only want it to unlock from drivers door?

Wed Mar 19, 2014 7:31 pm

Brianmoooore wrote: Driver's door microswitch is only for the deadlocking feature, but the one on the passenger door supplies the lock request signal.

Fri Mar 21, 2014 10:20 am

may be switching out all the lock mechanisms worthwhile?

Fri Mar 21, 2014 1:46 pm

Absolutely no point in changing perfectly good lock motors if they work.
Any theories on why the microswitches have gone missing?

Sat Mar 22, 2014 11:41 am

No apart from maybe if they used a complete aftermarket central locking kit only explanation, i can lock the car by microswitch in drivers door but not unlock?

Sat Mar 22, 2014 2:14 pm

Sach_UK wrote: maybe if they used a complete aftermarket central locking kit only explanation

Put up some pics. of the actuators, switches and ECU, then we'll know for sure.

Fri Apr 11, 2014 4:44 pm

so ive got round to the microswitches, drivers door isnt mounted on the plate, passengers doors microswitch is also not mounted but are both present just hanging inside each door? do i need them for the central locking to function?

Fri Apr 11, 2014 6:22 pm

Are you confused on how to ground a component? It just means make a connection between the component and any part of the chassis where it's bare metal. For example, one close to the drivers side footwell speaker would probably be the nut/bolt that holds the drivers seat in, but I'm sure there's loads around as there's loads of electrical components nearby.

Fri Apr 11, 2014 6:31 pm

Willeh -

doesnt that mean cutting some of the loom on the CLCU though,e g the specific colours requested to ground?

Fri Apr 11, 2014 7:00 pm

If you can see the pins of the circuit you're testing, you can just use any old bit of wire (as long as it can take the current), jam one end into the pin you're testing and put the other end onto an earth.

Fri Apr 11, 2014 9:24 pm

Driver's door switch is just for the dead locks. Passenger door switch is required for the locking to work from the key in that door.
Any idea why they are hanging? Mounting plates must be there for the lock barrels to fit securely.
You still haven't confirmed whether or not you have a locking ECU.

Sat Apr 12, 2014 2:04 am

Hi, yes i do have the locking ecu, the black box right?

Mon May 05, 2014 1:55 pm

Hi, okay so i have fitted the mounting plates with new lock barrels and microswitches on both sides now. it now locks from both the doors and unlocks from both the doors. The only thing i havent got working is the boot is locked shut and i cannot open it with the key, previous owner didnt give me the right key for it, any suggestions?

Mon May 05, 2014 2:02 pm

Prime suggestion is don't buy bodged about cars from penniless losers, but it's a bit late for that. Things like non matching keys are a good clue to what state the rest of the car is likely to be in.
Does the petrol filler flap lock and unlock OK?

Tue May 06, 2014 12:52 am

Bodged and fixable however isn't so bad especially if you raked it in at monopoly money prices! haha, yeah the petrol filler flap lock and unlocks fine. thanks for your help so far dude!

Tue May 06, 2014 10:12 am

Filler lock is on the same circuit as the boot lock, and further 'downstream' than the boot lock, so it looks like you have a problem!
There's no other non destructive way into the boot of a cab, and it looks like the lock motor has either failed or become disconnected.
One way I've used before (but not for many years) is to remove the number plate surround, then to drill a small hole in the back panel due north east of the lock button, as close to the black button surround as possible. Drill through the body, then through the sheet metal lock housing behind it, angling the drill to the left slightly.
If you've aimed correctly, the lever that the lock button engages with will be directly behind your hole, and a bit of prodding with a small rod should release the catch.