Central locking

jwthwaites96 · Post by **jwthwaites96** » Wed Feb 27, 2008 10:53 am

I'm new to the BX mechanics so recently when my central locking made weird noises I instinctively took the door pannel off and had a look.

I found the noise was coming from the central locking solenoide, so every time the lock unlocked the motor over-ran making an almighty errkkkkrkkk

sound. Anyways i disconnected this and had a mess around. I found that if i connected the white connector to the solenoide but not the brown connector the central locking all worked but without the motor over running, but if i reattached the brown connector the problem reoccured.

My question is - what does the brown connector do? is it the earth and is there a problem with me leaving it disconnected as long as i wrap it up with electrician tape?

Any advise is welcome.

Cheers

Way2go · Post by **Way2go** » Wed Feb 27, 2008 5:12 pm

Hi John,

Welcome to the forum.

More information is needed to diagnose such a problem, firstly model of car and its year. Have you referred to the circuit diagrams in Haynes? They are reasonable but you need to remember that they are handed the wrong way (ie LHD) which is significant for the locking system especially if the car has a remote ir.

If you remove one of 2 wires from the motor, theoretically it will not work as there is no circuit left so there must be another explanation here. ie are you talking about the drivers door and only operating it manually with a key?

Vanny · Post by **Vanny** » Wed Feb 27, 2008 7:16 pm

W2G, there are TWO connectors (each carrying two wires) on the posh spec BX's. The white connector is for the central locking/motor power. The other connector (brown in colour) is for the 'door open warning light' on the little display to the right of the coin holder.

Exactly why functionality would return on disconnecting the brown connector i dont know (unless i'm getting the connector colours mixed up?) as it is a simple over travel switch. Unless of course the switch is getting jammed, hmmm very strange

best bet, chuck in an alternative unit (there easy to come by as they rarely fail) and see if it is the unit at fault or the wiring!

Way2go · Post by **Way2go** » Thu Feb 28, 2008 1:59 am

Vanny, the lock motor connector is the Brown one, that's why I queried whether this was the drivers door and jwthwaites96 wasn't using the ir remote. Should be white & Green wires in it. I don't think that there are overtravel switches as the motors are electronically controlled by a timed pulse. So it is likely that the motor itself is mechanically dry, tight or seized.

Vanny · Post by **Vanny** » Thu Feb 28, 2008 8:53 am

the travel switch is for the DOORS OPEN display.

jwthwaites96 · Post by **jwthwaites96** » Thu Feb 28, 2008 10:58 am

Hi guy's,
thanks for all the advise, in answer to the questions you asked the car is a 1.9 Diesel (not turbo) its a H reg hatchback.
I did refer to the hains manual but they just told me how to remove it not really what the components do. I will have a look at the circuit diagram, but the last time i looked at that it just looked like a pile of spagetti.
I agree with you about the theory that both connectors would be needed for the circuit to be complete, thats why there is confusion on my part, I thought possibly the motor possibly could be holding a charge but it has been running too long now for that to be the case. I will thou have a look to see if the door opening indicator is working and that should answer that question.
You mentioned that getting hold of the motors is quite easy, personally i have found finding BX's or bits of BX's in scrap yards or breakers yards or even dealers near impossible, are there any yards/dealers you would recomend, I am based in bristol so near here would be great, but will be soon going to cumbria if they can only be found up there.
thanks again for all the help, keep it coming.

Way2go · Post by **Way2go** » Thu Feb 28, 2008 2:33 pm

jwthwaites96 wrote:theory that both connectors would be needed for the circuit to be complete

No

As both connectors carry 2 wires and the connector functions are totally separate, they are able to complete their own circuits even if the other connector is removed.

Brown Connector = Lock Motor
White Connector = LED for that door segment display

DavidRutherford · Post by **DavidRutherford** » Thu Feb 28, 2008 5:59 pm

My understanding is that the door locking solenoid has nothing to do with the doors open warning system, especially as when the door opens the lock solenoid doesn't move.....

I believe the white plug is the "detect the door has been locked/unlocked" connector, and the brown one is the "drive the locks" connector. Noted by the fact that the front doors have "master" solenoids with both connectors, and the back doors have "slave" solenoids with just the brown one.

... I say solenoid, it's actually a small hobby motor with a pinion on it, and a short rack. These do wear out eventually, so you may find a replacement one is the way to go.

Makes sense too, as if you remove the brown connector from the drivers door, it will still detect and lock/unlock all the other doors, but I bet if you try using the passenger door, the drivers door will not respond.

Way2go · Post by **Way2go** » Thu Feb 28, 2008 7:23 pm

DavidRutherford wrote:My understanding is that the door locking solenoid has nothing to do with the doors open warning system, especially as when the door opens the lock solenoid doesn't move.....

I believe the white plug is the "detect the door has been locked/unlocked" connector, and the brown one is the "drive the locks" connector.

I believe you are right and there is another white plug in the viscinity for this.

This part of the input system has confused in the past as this switch input was removed from the passenger door to use for the remote input as only 2 available on the electronic unit. But there are those that say that the contacts can be added back to the passenger door without problem so Citroen's rationale is difficult to understand if so.

kermit the frog · Post by **kermit the frog** » Fri Feb 29, 2008 8:14 pm

What is your location John
As i may be going to a scrap yard sometime next week to get some bit's for my BX and i could see if i can get a drivers door solenoid for you.

Regards Kermit

jwthwaites96 · Post by **jwthwaites96** » Wed Mar 05, 2008 1:05 pm

Hi kermit, sorry for such a late reply, sorry if it is too late, work has been busy. I'm in bristol horfield area, if you have already gone where was it you were going cos I could make a trip myself as I could do with some other its and bobs too, ie. drivers seat.

Back to the solenoide problem, the plot thickens!!! with only the white connector connected the central locking and the door indicator by the gear stick both work. so the brown connector remains a mistery!! any other ideas anyone?

DavidRutherford · Post by **DavidRutherford** » Wed Mar 05, 2008 3:09 pm

jwthwaites96 wrote:Back to the solenoide problem, the plot thickens!!! with only the white connector connected the central locking and the door indicator by the gear stick both work. so the brown connector remains a mistery!! any other ideas anyone?

a few posts up, I wrote:I believe the white plug is the "detect the door has been locked/unlocked" connector, and the brown one is the "drive the locks" connector. Noted by the fact that the front doors have "master" solenoids with both connectors, and the back doors have "slave" solenoids with just the brown one.

Now, I could well have got the colours of the plugs the wrong way around, but as an explanation goes, what more are you looking for?

I've since looked at the loom I pulled from a BX, along with the four door locking solenoids, and it is exactly as I'd assumed. One plug is the "detect" system, and the other is the "activate" system. Your master solenoid is broken, but still works to detect and hence drive the other solenoids.

kermit the frog · Post by **kermit the frog** » Wed Mar 05, 2008 5:22 pm

Hi John
I havn't been yet and the yard i am going to is near crawley in sussex so it's a fair way from you.
I know they have at least three bx's there and i know one has central locking.
I have had to delay my trip there till next week so if you are still interested i can still try and get the solenoid if you still need it
I also need a drivers seat but i think i have seen something on here about the front seats being interchangable and as the passengers seat gets less use it is probably a better bet.

Regards Kermit

Post by **docchevron** » Wed Mar 05, 2008 5:28 pm

I've got spare solonoids, and I'm also in Brizzle, sometimes...

You can have one gratis if you want it, but I suspect it's more likely to be a break in the wire between the door and A pillar..