Dash light go off/on

[nirbaer]

Hi
Suddanly i have the dash lights going off/on without relation to anything. Tougether with the lights goes off: speedo & tachometer, digital clock (clock being reset) odometer.
Other lights like turn signal, main beam and the rest of the electric things are not affected.
What can this be? Do i have to open the dash?
It's 2001 1.4L. There is no dash light dimmer.

[stevo67]

I know I say it a lot but a faulty alternator can cause these problems it plays havoc with your clocks etc.

[nirbaer]

I was thinking, due to the behavior, it should me a kind of a relay of electronic device which controls the voltage to the dash - but where is it? I didn't find anything like in the electric diagram.
Alternator charge and battery connections will be checked.

[nirbaer]

Alternator is o.k

[6Tricksta9]

I have the same issue, roughly.

Dashboard lights dim, dials get stuck or reset to zero, cd player switches off and my headlights get brighter. Often my revs wont reset either and end up idle on 1k.

I've been told to look at my earth points, though just looking at them will solve absolutely nothing. Guess the only option is to get an electrician to look at it!

You'd know if it was an alternator WAY before this stuff happens as your car will struggle to start, which it clearly doesnt.

Edit: A member told me to check for wires touching something they shouldnt. Not surprising if you have an after market HU.

[nirbaer]

So far I:
- checked all the fuses and replaced F8 (20A) just in case
- drove with voltmeter to see for any voltage changes/peaks - ok
- searched for loose earth connections
- disconnected the battery for 1 night - after this is was ok for 1 day and then back like usual - coincidence?

Anyway problem still there.
I noted on the electric scheme the dash has 2 connectors, one of 26 pins and the other of 18 pins, the one with 18 pins is the one related to the problem, the problem is there is no access to these connectors without disassembling half the car as they are behind the fuse box.
Also taking the dash out involves removing the steering wheel and airbag which I am trying to avoid.
Hope to solve this soon, as I see other threads (http://www.saxperience.com/forum/showthread.php?t=30227&page=2) with the problem which disconnecting the battery didn't help.

[stevo67]

Take the upper/lower plastic shrouds off the steering column,underneath are 3 13mm bolts take these out.Your can then lower the column down far enough to get the instrument cluster out mate.

[tom_lloyd_4]

from the sound of it the 2 connectors you are referring too are up under the glove box if you look up in the Passenger foot well you suld be able to see them

[Dom]

It will be something to do with the Alternator.

Once my wires from my Alternator were chewed up by a driveshaft, it sent my clocks spastic.

[DundeeUnited]

check earths also mate, happened to me about a month ago, eventually it lead to my car stalling at junctions and not restarting.

[DundeeUnited]

i just read ur post and realised youve checked earths so ill shut up

[nirbaer]

Take the upper/lower plastic shrouds off the steering column,underneath are 3 13mm bolts take these out.Your can then lower the column down far enough to get the instrument cluster out mate.

Thanks for the tip, I will do it.

It cannot be the alternator because the charging is o.k. (14V), and it can happen even when the engine if not working.

[nirbaer]

Found the bolts, but nothing can come out since all is wired and cannot be pulled off. Any advice is welcomed.
Adding 3 pics:
1. fuse box and the connector which comes from dash marked.
http://img233.imageshack.us/img233/4060/wire1custom.jpg (http://imageshack.us/photo/my-images/233/wire1custom.jpg/)

2. same from beneath.
http://img685.imageshack.us/img685/1295/wire2custom.jpg (http://imageshack.us/photo/my-images/685/wire2custom.jpg/)

3. look with plastic cover out
http://img267.imageshack.us/img267/9365/wire3custom.jpg (http://imageshack.us/photo/my-images/267/wire3custom.jpg/)

[Jaffaa]

I have had the exact same problem for 3 months. Can anybody tell me where to check earths?

[Jaffaa]

Any luck yet nirbaer?

[nirbaer]

Not yet

[nirbaer]

Took out the dash, connected pin no. 9 on the 18 pins plug directly to F8 (+12V to the dash) hope it works.

http://img256.imageshack.us/img256/968/img0512custom.jpg (http://imageshack.us/photo/my-images/256/img0512custom.jpg/)

Now the fuel gauge seems to no work as it goes to full 3 times on ignition and them dies...

[nirbaer]

That didn't help, neither connecting pin 9 (earth) directly to the frame.
Given all that I am starting to think the fault is with the dash board itself.
I will drive it like that for a while and see if something changes.
BTW I found here at least 20 threads with the same problems few had it solved apparently with battery disconnection and the rest have have no update - I guess problem is still there?

[Jaffaa]

Still got issues with mine, when your car does it does it feel like the engines under more strain like its trying not to rev as quickly or is that just me?

[nirbaer]

No it's just the dash light itself.

[nirbaer]

Fixed. The problems was with the dash PCB (power on reset mechanism failed and caused it to reset not only at power on).

[kev13]

Fixed. The problems was with the dash PCB (power on reset mechanism failed and caused it to reset not only at power on).

so were do i find the PCB? my car has just started doing the samething

[nirbaer]

Hi it's behind the steering wheel it has the dials on it (see post #17 (http://www.saxperience.com/forum/showpost.php?p=5792166&postcount=17))

According to the service manual you have to take off the steering wheel and airbag to get access to it but i managed to avoid it with some effort.

The way to test it:
Once you apply 12V to the small 18 pins plug (12V to pin 9, earth to pin 18), the voltage regulator 4725 should work, 12V should be on pin 1, 5V on pin 5 (output).
Then there is pin 2 (Reset Output) that apply reset signal the the microcontroller and unless the voltage there is 5V the lcs will not work since it is in reset mode.
I found that when the dash lcs was working ok the voltage there was 5V and when off it was 2.2V.
Until here is the diagnostics, to fix it, I disconnected pin 2 of the regulator 4275 from the PCB, and connected the PCB side to 5V (pin 5 of 4275) through 1kohm resistor for permanent reset signal.
The catch is there there is no power on reset now so the solution is to take out a wire from the PCB just connected to the resistor, the wire should go out of the dash and once connecting it to earth it will perform reset and everything should work.
This manual reset procedure should be done every time the car battery is reconnected (of F8 fuse).
That's it. And thanks to citroen engineers for electronics QA.

[stevo67]

When you say earths I take it you`ve checked the earths either side of the dash,where the carpet comes up?2, 13mm bolts iirc mate.

[nirbaer]

Sure. I saw you suggested this it in another thread and actually one of the 13mm bolts was a bit loose but that wasn't the problem.

[kev13]

turned out it was the alternator not working all a time for me put one on i had laying around and problem solved