Citroen XM Forum

Yep. I flashed my lights vigorously.... Still didn't understand!

Horn fixed. Turned out it was corroded plugs. Well one was full of water and the other sprang to life after cleaning the contacts and Wd40ing both. So at least I can toot elderly Yaris drivers merrily sitting at green traffic lights now.

Next issue, the door locks are playing up. Unlock on fob fine, open a front door and they all automatically lock and then unlock. Stoppers don't really move. Yet repeat but with a back door, they lock, stoppers down and stay locked. Leave a front door open and then open the other doors, nothing happens.
To me, and this might be bad memory, it looks like someone has had another go at the front passenger lock. It still works though. But this wasn't playing up yesterday. Odd. I expect it's micro switches. I want to replace the front door handles anyway, one because of the tampered lock and the drivers one has a chunk missing out of it. Old damage I think.

Anyway stuffed some Wd40 in the locks in the mean time. One thing after another with this car at the moment.

Russ... Somebody else mentioned this the other day but I deffo think its a case of 1 step forward and 2 steps back. When I plan on fixing something minor on mine I always imagine what's gonna break in the process...

Absolutely Ray. One thing about owning an XM. Never ever be surprised when it, or something goes wrong!
I'm sure there is a secret fleet of XM pixies that go around messing with them at night!

Checked the door handle with the photos I took after it had been tampered with. They are identical, so I doubt it's been messed with again.

Plot thickens. Just popped out to have another play with the door locks. Pressed in the passenger front puddle light switch and it activated the locks. Lock and then unlock. Replaced it with a spare. Door now opens with no issue. However, if you press the button in on the new switch it locks and unlocks. Probably a slightly sticky switch as the puddle light doesn't really light up unless you prod the button in and out. Even taking out the screw on the switch messes with the locks.
Tried the rear passenger one to see what that does. It does the same, but only locks the doors, just as using the handle. The other side, nothing. No issue, unless you use the door handles. Both puddle light switches were dry, and clean.

So that possibly means that it's something on the passenger side? Who knows.

Well this mystery is interesting. I replaced the passenger front door puddle light switch with one of the rears just to make sure it wasn't a fluke replacing it with a spare. It behaved. But as soon as I replaced it with the original puddle light switch, the locks go mad whilst doing up the screw. Then the locks misbehave when opening the door.
None of the other puddle switches activate the locks.

Took that switch out and replaced it with a rear one to test it. All fine. Put the spare puddle switch in the drivers rear and it works fine there. Left them in place!

Noticed that the drivers door puddle light is not working. Thought it's just a bulb. Got three spare puddle lights to check if they work. They do on the other doors, but not on the drivers door. When taking out the puddle light switch the screw sparked on the sill. Interesting! Tested the plug to the puddle light with a voltmeter. Got 0.02 at best.

The Windows and mirrors all work, the interior lights all work. But now I have got it so that the other three doors and the boot, all open without issue. No lock activation. So I believe and this has yet to be found or proved, the wires in the drivers door conduit are possibly broken, or insulation has fallen off and some wires are making contact.
Investigations continue tomorrow.

Sounds like something which should be earthed has lost its earth connection, and is using a nearby something instead. Bit like brake lights which end up bringing on rear lights and indicators at reduced brightness.
I would start by checking out earths, but no idea which ones. You could start by running a good earth connection to a few connections that should be earthed, and see whether anything rights itself.

I did think about the earths. But then they have been cleaned and sorted when I did the engine swap. Look again certainly.

May not be one of the main earthing points (engine bay and footwells), but just a small grounded connection elsewhere.

Grabbed five minutes to undo the sometimes sticky door connectors ready for tomorrow's probing. Flipping plug was full of water. No wonder it was mis behaving. All working now. WD40'd it and will sort it out tomorrow properly. Thank goodness it was just that.