W124 locks and infra red

crt

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I know this has been covered many times in various contexts but I haven’t been able to find anything quite on point with my accumulation of problems, which mean at the moment I can’t reliably lock and unlock my 1995 S124 E300D.

First of all, neither tailgate nor passenger key locks will work, either lock or unlock, and despite lots of WD40, a hair pin and surreptitious use of our electric toothbrush, it has not been possible to free the barrels, and to add insult to this, the hex bolt on the passenger lock is siezed and now has a bit of allen key lodged in it, meaning even changing the barrel there is now looking very difficult.

Added to this, the infra red is now not working. It was until recently, but then I had a flat battery, the keys became unsynchronised and, because the passenger lock doesn’t work I can’t resync them. Or at least I thought I couldn’t, but then I managed to get one to work partially by simulating the use of the key in the lock by locking and unlocking the passenger door in sequence using then inside handle.

The partial functionality is that one key will lock on the boot sensor, but won’t unlock on the sensor (the driver’s door sensor hasn’t worked for years). Central locking works on all doors, including the boot, by pressing the door buttons down amd unlocking on the inside door lever. When locking on the boot sensor, I don’t get the red light which used to indicate the alarm was armed. The alarm is not armed because it doesn’t go off when I unlock he central locking using the inside door levers (I am currently leaving the front passenger window open while puzzling through this).

I stripped the covering off the inside of the tailgate and now when I press the remote pointing at the tailgate sensor in the locked mode (as if to unlock) I can hear a faint electrical click which suggests the electrical side of the system is probably working, and that therefore the problem is likely to be on the vacuum side.

Assuming this analysis is correct, my question is, where do I go now in fault finding on the vacuum side? Or is there something else I should be looking at?

Many thanks.
 

mioba

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A hell of alot of things on the 124 are vac operated it is amazing.
Issue is that when a prob occurs tracing it is long winded.
Indeed I would be looking at the lines.
 
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crt

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Thanks. Am having second thoughts about the vacuum though, because all locks, inc the tailgate, lock and unlock from the doors suggesting the vacuum pipes must be ok, unless there is something special that happens in conjunction with the infra red. I will trace both electrics and vac and see where it takes me.
 

Blobcat

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A hell of alot of things on the 124 are vac operated it is amazing.
Issue is that when a prob occurs tracing it is long winded.
Indeed I would be looking at the lines.
I see what you did there… :p

I loved the Mercedes vacuum locking, so much nicer than the electric clunks

Thanks. Am having second thoughts about the vacuum though, because all locks, inc the tailgate, lock and unlock from the doors suggesting the vacuum pipes must be ok, unless there is something special that happens in conjunction with the infra red. I will trace both electrics and vac and see where it takes me.

If you can power the vacuum you can check the doors lock and unlock to isolate the vacuum side of the system
 

rayhennig

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Is it possibly an issue with the convenience control module. They are different if you have infrared; I don't.

I say that because I had an issue with windows/roof not closing with the remote lock and it was solved by installing a replacement module and generaly cleaning up contacts in that area.

I also had a battery drain from that circuit (Fuse 9? - can't remember) and it was solved when I changed a little vacuum module alongside the module.

Just some random thoughts.

Good hunting.

RayH
 


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