Another n00b query this one about Xantia dash lights failing

[Napoleon]

So for the second night the Xantia's dash lights are all out.

I don't think it's a fuse issue, as it happened on Saturday night when I drove the car back for the first time - and a whack on top of the dash got the lights back on.

Now no amount of bashing makes any difference.

The warning lights are on ok, it's the backlighting that's AWOL.

Is this common? Got a fix?

[Toby_HDi]

Have you actually checked the fuses this time around? If not, do so. Also, switch the fuse for the dash lights with a known working fuse. I have come across a couple of fuses that have blown even though it doesn't look like they have. It's worth a look.

Otherwise, I would say its a connection on the multiplug on the back of the dash (I assume its a multiplug - someone will correct me if I'm wrong)

Not much help but a couple of things to look at

Toby

[Napoleon]

You never know, stranger things have happened at sea.

I just wish it would stop raining so I could get out there and have a proper look at the car!

Thanks for the reply.

[Xaccers]

Would a failed brightness adjuster give full brightness or plunge it into darkness I wonder?

[Napoleon]

I had a good look thru the manual yesterday and I don't remember seeing anything about a brightness adjuster.

Was there one on all models?

[red_dwarfers]

I wouldn't have thought that it was the brightness adjuster, as it doesn't plunge you into darkness I don't think. Also a sharp blow to the dash wouldn't make it change its mind.

The brightness adjuster is just to the right of the steering wheel movey uppy downy thingy, its always worth a try!

[CitroJim]

My 1.9TD had only one good bulb in it when I first had it so don't dismiss the possibility ALL bulbs have blown.

If the brightness control goes open circuit (most lilely failure mode for these wirewound pots or rheostats), the lights will go out. Pop the pot out of the steering wheel cowl (only clipped in) and short circuit the two wires in the plug. If the dash now lights up, there's your problem.

If it all gets very difficult, I'll dig out the circuits.

[DickieG]

My Hdi had a brief period of suffering from this problem where a quick thump on the steering cowling or a twiddle of the dash lighting rheostat (under the cowling) would sort it out, I was about to replace the rheostat a couple of weeks ago when it sorted itself out my money is therefore on a fault with the rheostat.

[Napoleon]

The lights are back on tonight, which is gracious of them...

Where on earth do I start when dismantling the dash/console? Got to find a plug somewhere there.

Could be worth having a dead Xantia on the road just to practice dismantling.

[vince]

Hi Tim,

mine has an intermittant couple of bulbs on the dash that dont come on all the time. like you said, a tap on the dash gets them going again.

I spent 2 years trying to fix the same type of problem on a VW Passat, the fault was where the multiplug plugs into the back of the clocks.

On a citroen, i am presuming the fault lies with slightly dry joints in the bulb holders....or in your case, on the lighting circuit.

There is no way round the fix which would be to strip the clocks out and investigate the problem.

From my experience, dash lights on Citroens arent amazing when it comes to connections.

[Napoleon]

Why shouldn't a connection be dry though? Surely that's the idea innit?

[Xaccers]

Why shouldn't a connection be dry though? Surely that's the idea innit?

Dry joint with electronics means that it's not making a contact (it doesn't mean there's a lack of moisture!)

[Napoleon]

So it could be sitting in three inches of water and still not work?



Just kidding about that.

When I drove the car back the other night, it rainings cats and dogs and I was leaving a service area and could barely see where I was going, so I can see (or not) why the OP did this thread.

I want to fix my lights now I've read this.

[Clogzz]

a whack on top of the dash got the lights back on

If the whack is hard enough for the steering cowling to feel it, the rheostat may still be intermittent.
There are plenty of wires going into the instrument panel, and all background lighting is a single wire from the rheostat.
I’m fiddling with that now, and the rheostat is out, causing total darkness of the binnacle, but with all function and warning lights still working.

Maybe try a more ‘localised’ whacking around the brightness adjuster.
Rheostats often also benefit from a squirt of holy water.
If that doesn’t help, these pictures are the look of what’s next.
The second picture is from Xantiaclub Nederland, with ‘achtergrond verlichting’ circled in yellow being the 8 backlighting bulbs.




Edit 3:35 PM … delayed reaction:
The brightness controller also feeds the clock bulb and heater slider lights.
If the clock, sliders and dash are in the dark, it’s the rheostat.
If the clock and sliders are lit, and the dash is in the dark, then the fault is in the instrument panel.

[NeaU]

HI!
My problem is something similar.
That begun when I was testing that wheel under the steering column that controls the brightness of instrument panel background lights.
These lights begun lit when turning ignition on regardless of whether the headlights are switched on or off (0 or ON) from the steering column switch, but after a few days they disappeared completely. All the warning lights works as they should. I checked the rheostat (under the steering column) with a multimeter and its seems to work fine because of the resistance changes when rolling it.
None of wires to rheostat has no power. Could it be that simply that steering column switch is partial out of the game???