citroen xantia 1.9TD Preg VSX overheating?

falling-out-with-my-car · 16 Jun 2008, 15:16

Hi, my fathers xantia P reg 1.9TD VSX is over heating, he seems to think that the fans are not running when he is stuck in traffic, it doesn't boil over when he is moving along the motorway only when stationary.

could someone please throw some light on the location of the coolant sensor/sensors that trip the cooling fan/fans please?

Thanks in advance.

Nigel.

Unread post by **CitroJim** » 16 Jun 2008, 18:26

Hi Nigel,

It's very unlikely to be the sensor. However, disconnect the brown Bitron sensor on the thermostat housing and if all is otherwise well, the fans will run at top speed with ignition on. This is a failsafe to guard against sensor failure (they usually fail open-circuit) causing overheating.

I suspect you'll find the fans remain silent when you do this. The fault then is likely to lie with the trio of relays between the fans. Clogzz, our resident fan specialist, has posted several times showing how a relay contact can overheat and lead to problems.

Have a look at recent postings by Clogzz on this subject for further advice. use the search function and search on username.

Unread post by **RichardW** » 16 Jun 2008, 21:30

citrojim wrote:the fans will run at top speed with ignition on.

When I tried this with my 97 VSX TD the fans came on with the ignition OFF - and refused to go off till I turned the ignition on again.

Unread post by **CitroJim** » 16 Jun 2008, 22:25

RichardW wrote:
citrojim wrote:the fans will run at top speed with ignition on.
When I tried this with my 97 VSX TD the fans came on with the ignition OFF - and refused to go off till I turned the ignition on again.

I've just tried it on my 2.1TD Richard. In my case they ran only with the ignition on

Interestingly, after disconnecting the Bitron and hearing nothing, I turned on the ignition and they firstly started up on slow speed and then after a second or so, roared off at high speed. I did it twice to make sure I was not hearing things.

Mine are incredibly noisy I find. Eiter they're well worn or seldom run and did not like being woken up

In any case, I reckon they're not long for this world

admiral51 · Unread post by **admiral51** » 16 Jun 2008, 22:39

IIRC the fans will only run if you remove the sensor plug with the ignition on. As Jim said they should start on slow speed first for a few milliseconds and then kick in at full speed. If you then turn the ignition off both fans should run at the slow speed until such time as
1. The plug is reconnected and both fans should stop
2. The ignition is turned back on in which should set the fans on full speed until plug is reconnected

I think the reason for the slow speed once ignition is off with plug disconnected is to do with electric fan system to cool the engine after the sensor has detected it needs to turn them on but the ignition is switched off before the temp is low enough to cancel them

Someone must know what type of system it is but i cant remember the name of it

Hope this helps
Link to the fan wiring diagram

Colin

falling-out-with-my-car · 17 Jun 2008, 13:19

Thanks for all of your comments but, the fans check out ok the relays are all good there are no blown fuses and the fans still will not run at all even with the aircon switched on.

there is no thermostat on the radiator like some models.

I have phoned our local citroen garage and they say it is probably a fault within the bitron box only trouble is they dont know where the Bitron box is which seems typical of citroen.

Any Ideas please?

regards Nigel.

Activamadness · Unread post by **Activamadness** » 17 Jun 2008, 13:36

Hi Nigel,
The Bitron box is under the nearside headlight, and a pig to get at!
You need to take the headlight out, and under the panel that the headlight covers (if that makes sense) is where you will find it
It isnt easy to get at!
I have had similar problems with my activa, and it turned out to be the fan motors, and bad earths
Good luck!
Jonathan

Clogzz · Unread post by **Clogzz** » 17 Jun 2008, 15:10

Clogzz, our resident fan specialist

Thanks Jim,

this is what I look like because of my obsession with fans.

no blown fuses

Not sure if ‘P reg’ means Mk II, that has an under-dash 5 Amp fuse to feed the top right relay coil.
On the Mk I, it’s also 5A, but in the under-bonnet fuse box.
The fan fuses are the two red ones closest to the battery.

falling-out-with-my-car · 25 Jun 2008, 21:05

oops my stupid mistake the fans apparently don't work at all dad checked the resistance and it would seem that they are all but slightly intermittent, so he is blamming the brushes and is considering either trying to replace the brushes or replacing the fans completely.
Aparently all the above tests failed also the fans are well and truly dead.

regards nigel.

Clogzz · Unread post by **Clogzz** » 27 Jun 2008, 13:46

Tapping the fan motors with a mallet or small hammer may sort of ‘reseat’ the brushes.
Brush changing topics here:

http://www.frenchcarforum.co.uk/forum/v ... hp?t=10752

http://www.aussiefrogs.com/forum/showthread.php?t=35927

falling-out-with-my-car · 10 Aug 2008, 17:49

righty then the fans have been out and check out ok so no problem with the brushes as first thought the relay connections were a little corroded and have all been cleaned the fans are back in situ and the engine was heated up over 45 mins on an extreemly hot day the fans just wont kick in at all not even at slow speed the fuses all check out ok the brown plug contacts on the thermostat housing are clean to, just dont know what to check next???

any more ideas please people???

Clogzz · Unread post by **Clogzz** » 11 Aug 2008, 13:31

Disconnect the brown sensor plug to see if both fans go to high speed.
If not, you may need to go chasing voltages with a test lamp.