E39 528 rear door won't lock

[digger_R]

I've just noticed that my rear offside door is not locking when I use the central locking - is this a common fault or does anyone have any info on what this is likely to be?

I don't really know where to start looking - I changed the battery recently so it isn't that

[dan101smith]

There's an actuator in each door that locks/unlocks the door - if it is just one that isn't working, then I'd start by swapping that out.

[HRG]

Multimeter, door skin off, find the problem. You'll either get a 12v signal on one of the wires or you won't when you actuate the locking. It could also just be mechanically stuck. Sorry, but I don't know the colours of the wires in there.

If you're not getting a signal on the wires, check the umbilical from the door to the chassis. Wherever wires flex is where they usually break.

[digger_R]

a slight update - I managed to push it down from inside. Subsequently when I used the fob I can see the door stopper(?!) move down about 3/4 mm but still not into the 'locked' position.

Is the door skin off and check likely to take long (hour or so?)

[HRG]

Not done it on the E39 but door skins are not usually too bad. You might break a couple of plastic clips or tear the inner covering but nothing a bit of tape won't fix If you break some clips they'll only be pence and you should be able to get some tomorrow.

[digger_R]

excellent - is there anything PH can't fix?

[HRG]

Only the layout of the Pie & Piston apparently