Citroen XM Forum

Well its been a fruitless evening.
After the fan trouble on Tuesday they ended the day not running at all, this evening I removed the air filter housing, intake pipe and shuffled the lhm tank to access the connector that seemed to be causing the trouble, it seemed clean and what I thought were chaffed wires were (in the light of day) just dirty marks. Turned the ignition on and there were no temperature warnings. The car would not start though which its not done before, after several attempts the starter motor sprung into life and it fired up, ran it up to temperature and the fans kicked in and out as they should, restarts fine.
Wiggled the connector again and couldn't provoke any bad behaviour so I put it all back together............not much else I can do with it all working.

Sorted out the o/s rear lamp unit earth so no more brake light failure warning while indicating so that's good.
I think I will just have to drive it and see if I can make it happen again its just strange that oh Tuesday I found the offending connector which seems to be dedicated to the fans and was doing all sorts of odd things when touched even slightly but is now sound as a pound.......? Odd

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LOL. I now the feeling.

This evening I've fitted a new driveshaft CV gaiter and even though I jacked the car up on one side some gear oil was lost into a clean tray.

No problem i hear you say....apart from I cannot get the fill plug out...and it's now knackered.

Ouch, you win with that one Will, hands down.

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Dean, it's sod's law that wiggling intermittently bad connections often seems to provoke them into working, so that you're left trying to pinpoint a fault which has annoyingly gone invisible! Would be much more helpful if the failure stayed put - at least there'd be something to look at.

When you say the engine wouldn't start, did you mean not crank or not fire?

It wouldn't crank Chris, just got a relay click in the main fuse board, reminds me of bad start inhibitor relay contacts but they are all good and have been covered in copper slip for years after the problem reared its head. Wiggling that relay didn't make any difference but it starts on the button now. It was just last night for about 5 ish attempts.

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If it fails to crank again (and you have the opportunity), it would be good to run a test lamp round the starter circuit, working from the starter motor backwards via all the relays, inhibitors, etc, ending up with the IGN sw and its supply. Somewhere along the line there must be a dead spot. Tedious to do in practice, and not a roadside job outside the supermarket.

Pull the connector apart, clean the contacts, grease, and put it back together. There might be some corrosion due to the car standing for so long and your wiggling scraped through it.

Unfortunately will its a bit more involved than that, the cabin loom that does all the dash sensor supplies for temp charge light, starter etc etc has suffered the ravages of heat and time, its now removed and undergoing surgery, going to be fun trying to source the correct replacement plugs! Where all the separate leads converge in the loom proper they are all shorting together even if the insulation at the plug end is good, surprised I've not had other issues before now to be honest

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Bosch EV plugs will do it although they usually only come in black and don't have the tongue to stop you plugging it in the wrong place which I'm not keen on, will have to get some coloured insulating tape, just trying to find some connectors pre wired as that will make life easier.

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Dean, is all that heat damage from the under-bonnet area?
I have never seen such havoc, unless caused by a neighbouring cable being forced to carry excessive current because an earth or something failed. A failed/partial engine earth strap can throw destructive currents onto the other connection cables.
Cannot be all down to roasting ambient temps, surely?
Any wiring damage elsewhere?