855:Tailgate not always closing/opening with central locking

[Py]

Hello,

I (still) have my 97' 855 which I'm very happy with. Just passed the 142k km mark (88k miles), and obviously still going strong!

The tailgate lock is slowly getting annoying however. After fixing all the rattles, it now starts to erratically refuse to obey to the central locking (key based-no remotes). When it happens I have to use the key in the tailgate lock to open/close it, which works flawlessly each time.

Basically, when I activate the lock from the driver's door, everything closes/opens properly, but sometimes the tailgate won't. It is quite random, and could be on closing as well as on opening.

I got the complete tailgate trim off, got the whole lock mechanism out, looking for some obvious problem, but found none. Everything is operating smoothly, and looks nearly brand new. So I cleaned the old greased, applied proper fresh replacement, and put it back in the car.

For a few days, I thought it was sorted, but it was probably just murphy's law playing with my nerves. It started again a few days later... As the trim is still off, I had a chance to go have a look inside the car when the look refused to work, to see if something was blocking it, or if it was hard to operate. But it wasn't. A gentle pressure on the part which is normally moved by the electrical actuator, and the lock toogled its position...

So, I'm somewhat confused... Is there something that can go wrong in the mechanical part of the lock? As I said it looks very clean and nice, and it seems to be solidly engineered...

My next guess is the actuator getting weak... Could that happen? Is a replacement actuator available alone, or am I supposed to buy a complete lock mechanism? Probably won't be cheap!

Last idea (but I don't want even want to think about this one) is some bad contact (plug at the lock end looks good and clean) or damaged cabling somewhere in the circuit... Fact is that central locking of all other doors _from_ the tailgate always works. Never encountered any fault when closing the car from there. So in my mind circuit should be OK, but it is probably a little to fast a conclusion.

Any insight on that annoying issue? Thanks in advance!

Py

[FCPEURO]

I have the exact same issue on my 850 wagon, but I have not had a chance to look into it more then you have. I have a feeling that it is an issue with the actuator itself because I tried to clean the contacts with no resolve.

[Ozark Lee]

Check the wiring at the point where it goes into the tailgate. Over time the wires start to break where they flex back and forth. The wires can look good but still be broken inside of the insulation.

...Lee

[Py]

Hi there,

I checked the cabling at the tailgate hinge, found nothing looking bad. I stretched each wire, and they all felt solid. So I refitted everything and assumed the fault wasn't there.

So next step, I ordered a complete second hand tailgate lock assembly on ebay (2nd hand because new is 120€+). Fitted it about 10 days ago, and since then my tailgate has always locked itself when ordered to do so by the central locking system. Not a single mishaps.

I consider this fixed! Thanks for the advices given.

Merry Christmas,
Py