Central Locking Issue

[Jim320i]

Had a search on here and come across a few people mentioning black and red wire mod?


Anyway, issue is, my locking doesnt seem to want to work anymore, last night I got home and it wouldnt lock so car has been unlocked all night...

For some time now its been playing up, I try to lock it, the key turns but nothing locks, the central locking relay thing in the driver footwell sometimes makes a noise but not often... It locked everytime before last night but sometimes it took a few turns to go, it wouldnt go at all last night


Anyone guide me to what is the fix and what I will need part wise if any? And if I do need parts, do they need to be prefacelift specific? As I have everything from the convertible and can help myself to the touring bits if need be...

Any info?

[daimlerman]

Now then,Fifi!

Start by reading through this link;

http://www.e30zone.net/e30zonewiki/inde ... g_problems

[Jim320i]

Ohh dear... Usually Im one of the first to check the Wiki for other peoples issues, didnt think to look on there for myself.

We should get directed to there before posting in tec help...

[daimlerman]

Those are the common faults and the red/black wire mod.

If you are still struggling after working your way through those items,post up with what you have tested/tried and see what comes back.

As you have a decent parts stash,simple substitution will help you!

[Jim320i]

Ok, had a read through.


Replaced the central locking relay with one I know works, still have nothing happening, no noise coming from the relay, locks do nothing when I turn the key.

Checked inside the door plug in and all looks good and clean in there.

Havent attempted the wiring mod yet as unsure to how this will fix it?

Does it sound like a fault that could be cured with the wire mod? Or does it sound like its failing elsewhere?

Could it be a matter of the actual driver door lock not catching somewhere which is causing it not to pick up that it needs to be locked as the relay makes no noise, which I assume no singals are getting to it?

[daimlerman]

Do the red/black wire mod regardless,you have checked for a blown fuse?

Point about the wire mod is that there is no point in a live feed circulating through the door harness,and it does sound like you have a live feed issue somewhere.
Does the driver's door lock with the key?
Does the boot lock with the key?
When you lock at the boot,does the rest of the car lock?

[Jim320i]

Checked over all the fuses, they all looked fine, need to find which one it would be though and just check again... May aswell and replace it for a known working one.

The driver door doesnt lock with the key at all.

The boot doesnt either but never has, Since I have had the car its only been lockable from the driver door, but never anything of it...


Gonna go and give the red and black wires a quick go now and see what happens.

I shall report back shortly.

[Jim320i]

Ok, looking at the wire mod, i'm slightly confused...

I see the black cable, I see a red/black cable and I see a red/brown cable...

Which one am I after and what am I doing with it? I thought I was looking for a plain red and plain black from reading the wiki and then link them together?

Very confused at the moment

[Jim320i]

Found them and did the mod... Although it hasnt changed anything, still not working.

Really starting to think its the actually locking mechinism as when it did lock before, it would always unlock with one turn... I have a feeling something it broken inside and isnt catching for when I want it to turn... Door card off and gonna investage there now.

[LLamaFarm]

sounds like its ur lock barrel, you can test the lock signal from the door. its the blue wire and white wire lock/unlock signals, check a wiring diagram though been a few months since i messed in that area.

[Jim320i]

Narrowed it down to the door catch itself... The lock turns but it wont budge the inner part of the door catch... When I pull on the relay part on the steal lines it pops up and down easily locking and unlocking, when trying to turn it on the key, the arm on the catch doesnt move enough... Closer inspection and one of the springs inside look like its half hanging out and its a sealed unit, so after a new one, just need to find out if they are different from prefacelift and facelift as I have on in a convertible door I can strip down...

[daimlerman]

Remove the latching gear,clean and lubricate,work by hand until it is light and smooth in operation.

[Jim320i]

Already attempted this Malc. I think something inside has come loose as there is a spring at the top I can see half of... I'm gonna get the one from the cab door later today and check that one over, hopefully its the same kind and I can just use that...

[daimlerman]

Whilst you have the door in bits,look very carefully at the lock barrel.

They fail at the L shaped bit that operates the fork on the latch,unlubricated catch often means overloaded barrel....
A 'lock repair kit' is about £20 from the stealer and gives you a bag of bits to build up a new lock barrel to suit your existing key.

[Jim320i]

Thanks for that Malc. I'll be inspect it all properly tomorrow. Havent had a chance today as been extremely busy and now the days are shorter and colder I didnt manage to get out to have a look.

When I was tinkering around the other day trying to find the fault, the L shape part you mentioned seemed to be doing its job just fine, But I shall check it over just incase. I have the convertible door still in one piece so I can cross reference the way it should all opperate when turning the key with any luck.

I'll report back if I find anything else and hopefully when its working again.

[Jim320i]

Ok, though I would update just so if anyone searches for the same issue in the future...


Replaced the inside door catch mechanism with one from a later convertible... So Facelift and prefacelift catches work in both... Although I had to mess about taking a couple of rubbers and little bars from the older onto the newer...

It didnt sort my issue straight the way, I then also replaced the barrel, and now it works, although 1 of out 10 times or so it doesnt pop all the locks back up, but another turn and its fine...

It was both the barrel and the catch that wear broken... Although I cant seem to see the fault with the actual barrel

[Brianmoooore]

although 1 of out 10 times or so it doesnt pop all the locks back up, but another turn and its fine.

Try a slight adjustment of the lock motor in its slotted mounting holes.

[Jim320i]

That is the section in the lower part of the door? Red & White box? This was one of the problems I found yesterday whilst trying to get it set up. I'd think it was right, close the door, then it wouldnt open again.

I shall have an attempted and tweeking it some more later when I put the door card back on