Xantia earthing points

pprado · Post by **pprado** » 25 Aug 2007, 14:25

My Xant completed 10 years and is having some strange sypmtoms, like the internal fan going almost full speed when I push the brake pedal... Now my stereo would wait for some seconds to turn off after I turned ignition off also...

I am willing to locate and clean any earthing point between the panel and the front of the car - maybe running a earth wire, to improve grounding, if needed.

Does anyone have some diagram, or know the location of the points?

Mandrake · Post by **Mandrake** » 25 Aug 2007, 23:00

Hi Pedro,

While it could be earthing related, I would say it is almost certain that your car has the imfamous ignition switch contacts problem affecting the blower motor !

Unless you have had the car from brand new, it is almost guarenteed that the switch contacts that power the internal blower motor have failed, and that a bodge job repair has been done which involves running the fan directly off the main pair of contacts that run everything else including brake lights.

In time those contacts too will start to fail due to the heavy current drain of the fan and you will get symptoms you describe - random loss of control of fan speeds, radio/fan/brake lights interacting with each other etc.

Please have a look at the following thread:

http://www.frenchcarforum.co.uk/forum/v ... hp?t=21372

You'll see that my car, at 8 years old, already had this bodged modification applied by someone. The solution is to run the fan from a relay as I describe in that thread. I have done this mod on two cars now with no reoccurances of any symptoms.

Regards,
Simon

pprado · Post by **pprado** » 26 Aug 2007, 15:06

Hi Simon,

I have dismantled the ignition barrel and cleaned the copper contacts with a wire brush from a dremel... It became new. That was some 1-2 years ago, so maybe the fault did develop again.

But why would the blower get MORE voltage if I press the brake pedal?

Anyway, I have read that thread before and felt like that´s the permanent fix, so I´ll be doing that also. Anyway, I still think cleaning the earthings can do overall good...

Mandrake · Post by **Mandrake** » 26 Aug 2007, 21:04

pprado wrote:Hi Simon,

I have dismantled the ignition barrel and cleaned the copper contacts with a wire brush from a dremel... It became new. That was some 1-2 years ago, so maybe the fault did develop again.

Absolutely - the contacts are simply not rated highly enough for the current drawn by the blower - they all fail, and it is not a matter of if, but when - so if you have already had that problem, I would say its a fair bet.

But why would the blower get MORE voltage if I press the brake pedal?

It doesn't - but the fan controller gets confused by low voltage, and will tend to lock on the current speed or jump to a random speed after low voltage - and once that happens it stops responding to the speed slider and the only way to "reset" it is to turn the ignition off and on.

If you find the speed control is unresponsive but then works again after turning the ignition off and on it sounds exactly like this problem.

Anyway, I have read that thread before and felt like that´s the permanent fix, so I´ll be doing that also. Anyway, I still think cleaning the earthings can do overall good...

I would definately follow the mod in that thread, and then see if there is any remaining problem, otherwise you could just be chasing ghosts...

Regards,
Simon