E30 central locking nightmare....continued.

[Phil-E30]

Afternoon all, bit of an issue with the central locking on the E30.

Went out to unlock the car and when I turned the key the only door that opened was the driver door. The passenger door, two rear doors and the boot all stayed locked. I am unable to open the rear doors at all but can open the passenger door and boot lid using the key in them individually.

What would be causing this issue and how do I go about resolving it? I had a spare actuator and tried that but it did nothing.

Cheers in advance for the help!

[daimlerman]

Two potential issues.
The c/l module hides behind the speaker/grille in the driver's footwell..
The thermal fuse within this unit could have failed,easy fix,re-attach without adding solder.
Whilst you are in the area,pull out the hank of harness leading to the A pillar socket and carry out the 'red/black wire mod'...this is detailed within the zone wiki...but in essence removes the loop of this wire passing through the driver's door,eliminating most of c/l locking problems.

Welcome to the madhouse,BTW

[Brianmoooore]

without adding solder.

[daimlerman]

without adding solder.

That's what I wrote....

[Phil-E30]

Cheers for the help daimlerman! I have since done the fix on the c/l module....with solder? I am guessing your "without adding solder" was a joke?

I had everything back together before I read this though and didn't do the red/black wire mod. Should I get it all apart and do this just to be safe do you think?

Cheers for the welcome too!!

[Brianmoooore]

NO IT WAS NOT A JOKE! If you have 'repaired' it with regular solder, or even worse, the lead free stuff that the green brigade have foisted upon us, your central locking now has no viable overload protection. A dangerous state of affairs when the original cause of the thermal fuse operating hasn't been determined.
Go back and do the red/black wire mod. - this is important for reasons other than to do with the central locking, and I advise you to replace the locking module.

[jmc330i]

Cheers for the help daimlerman! I have since done the fix on the c/l module....with solder? I am guessing your "without adding solder" was a joke?

No joke!
Low melting point solder is used on this joint. Adding normal solder could cause issues... I'm sure Brian will be able to explain.

[Phil-E30]

I will go back through and do the wire mod. Is it a simple process?

I repaired the module with solder, but it wasn't lead free solder, I always source solder that contains lead as the modern stuff is absolutely shite. Either way, you now think what I have done warrants replacing this module? Is there no way I can do a better repair job?

[daimlerman]

The thermal link used low melting point solder,all you needed to do was to warm up the link and re-make the joint....if you removed the special solder and used ordinary stuff,as Brian says,the module is not safe to use as there is no built in safety cut out.

Red/black wire mod is simple to do if you can solder/heat shrink a couple of wires together.It eliminates a permanent live wire running through the A pillar socket,this tends to corrode and causes all sorts of mayhem that often is not directly related to this connector.

[Phil-E30]

I think I should be up to the red/black wire mod.

I am annoyed at myself for making the mistake with the solder. The walkthrough I read simply said to solder the broken connection and re-establish it. It didn't mention low melting point solder or anything of the sort. I probably should have known better! But if I am not mistaken does solder containing a high lead content not have a low melting point anyway?

[daimlerman]

But if I am not mistaken does solder containing a high lead content not have a low melting point anyway?

That's far too technical for me to answer,I'm afraid!

TBO,I have only needed to open up a c/l module once,and as I am a known tight git,seeing lumps of solder on both parts made me as it was just about a free fix(well,I had to pay for the electric...)

[Brianmoooore]

It didn't mention low melting point solder or anything of the sort.

daimlerman did point it out, and then I emphasised the point!

'Ordinary' solder is about 60% lead and 40% tin, and has a melting* point of around 180 - 190 degrees celcius - considerably less than the lead free rubbish, and still far too high for the thermal cut out application.
I don't know the exact spec. of BMW's solder, but I suspect it's an Indium/tin mix, which can have melting points down to around 120 degrees.
Note that if the original module in your car had 'tripped', then it did so for a reason. The sprung resistor was doing its job.
If the reason hasn't been identified and rectified, then you are pushing your luck using a module where the safety system has been bypassed.

*Not strictly a melting point, more the temp. it softens.

[Phil-E30]

Brian, I had done the job before I got back to read the replies from you and Daimlerman, I wouldn't have disregarded it had I seen it

What do you think would be the possible causes of the sprung resistor needing the connection re-established? Surely there is a chance, as with most soldered connections that it simply perished?

[Speedtouch]

Indeed, a solder joint under sprung tension may have just separated because of fatigue, and not necessarily because of overheating.

[Phil-E30]

I also understand the issue with the fact that my solder my not melt at an appropriately low temperature, but are there any severe risks from this?

Like I said, I regret the mistake and the fact that I didn't get the chance to read on here before following instructions from elsewhere that didn't mention low temp solder.

[Speedtouch]

I wouldn't have thought so; the C/L has a separate fuse (# 27) in the fuse-box:

http://www.e30zone.net/e30zonewiki/index.php/Fuse_Box

So, if things get really nasty, that will blow, to protect the rest of the electrics.

[Brianmoooore]

the C/L has a separate fuse (# 27) in the fuse-box ........ that will blow, to protect the rest of the electrics.

Unfortunately not. Fuse 27 is provided for short circuit protection, while the thermal fuse is provided for overload protection. Two very different things.
A similar situation is found with the electric windows, where there is both a fuse and a thermal overload to cover both situations.
Even the electrics in your house are protected for both eventualities (and earth leakage as well). If you look inside a domestic MCB you will find two distinct mechanisms to release the contacts - a bi metallic strip for overload protection and a solenoid for short circuit protection.
Fatigue only occurs with soldered joints if they are subjected to cycles of thermal or mechanical stress, neither of which should apply in the application in question, if all is working as it should.

[Phil-E30]

Well I suppose there isn't much more I can do now. It is done, and everything is working ok for now.

As I said Brian, what sort of thing would cause this to happen? What would have prompted my needing to repair this?

[Phil-E30]

Further to the earlier reported issue (which is now resolved, albeit slightly incorrectly) there is slightly more minor issue, which is rather annoying.

When I use the lock on my drivers door to lock the car, it slips in to the deadlock position far too easily. I almost have to try to stop it going in to deadlock, when before there were 3 easily defined positions in the locking rotation, unlocked, locked and deadlocked.

What would be causing this issue and how would I go about rectifying it? Many thanks again.

It's great so see such a helpful and welcoming forum! They are awesome things when people use them correctly!

Cheers

[daimlerman]

Sounds like you need a door lock repair kit.Available from your local friendly stealer for about £20.
What you get is a bag of bits to enable you to build up a new door lock barrel to suit your key,it's not as difficult as it sounds,try to hunt up a post by 'bigwyn',he took some good photo's to go with a detailed write up.



Take the old barrel out of the door,it's held by a large C clip,pulling it apart by removing the roll pin at the inner end will most likely give you a broken bit as in my photo above.

[Phil-E30]

Ahhh, there we go! I will get the barrel out of the door for further inspection tomorrow.

Once again, much appreciated Daimlerman!

[daimlerman]

Just to amplify,the r/h end of the above operates a fork on the door latch,un-bolting and removing the latch(a fiddly task)cleaning and lubricating all visible piviot points with light oil,the stuff you use on the kid's bikes is perfect,operating by hand until the latch is free and smooth in operation will also help.