Xantia 2.0 HDI late model with AC - radiator fans

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Pshemsky
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Xantia 2.0 HDI late model with AC - radiator fans

Post by Pshemsky »

Hello Guys!

I would like to ask You how fans on late 2.0 HDi Xantia (Y reg with AC) should work ? From previous posts I know that fans operate in different way in later models. Only D/S fan runs in normal temperatures and second one starts when AC is on or engine temp will go above 100 or something like this (if I'm correct).
I'm asking because in my situation first fan start going even when temperature is below 80 - just switch on for about 20-30 seconds and then goes off. I've tried to switch AC, but looks like there's no reaction at all from second fan. The temperature never goes above 81-83 degrees but one of fans comes on in random moments (even when engine is still cold).

I have loads of spare cooling system parts (including the whole housing, relays, motors, etc) so I would appreciate if someone could provide a description of correct fan operation and advice what I should check/replace to make sure all works as it should.

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Hell Razor5543
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Re: Xantia 2.0 HDI late model with AC - radiator fans

Post by Hell Razor5543 »

If the a/c is on (or the heater controls are set to demist the windscreen) the fans WILL be on. When the demist option is on the a/c is on (stealthily; the a/c light is not on), as it helps to dry the air coming into the vehicle. This happens on demist even if you have NOT turned on the a/c yourself.
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Re: Xantia 2.0 HDI late model with AC - radiator fans

Post by MikeT »

What I do is disconnect the coolant temp sensor with engine running as this should cause a cooling fail-safe mode wherein both fans should start, at slow speed briefly before quickly ramping up to full speed - so if you try this don't dangle anything near the blades! If one fan fails to work, the electricals need troubleshooting.
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Re: Xantia 2.0 HDI late model with AC - radiator fans

Post by GiveMeABreak »

Hell Razor5543 wrote:
09 Dec 2018, 15:12
If the a/c is on (or the heater controls are set to demist the windscreen) the fans WILL be on. When the demist option is on the a/c is on (stealthily; the a/c light is not on), as it helps to dry the air coming into the vehicle. This happens on demits even if you have NOT turned on the a/c yourself.
I think he's on about radiator fans not heater fans James.
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Re: Xantia 2.0 HDI late model with AC - radiator fans

Post by GiveMeABreak »

For the Series Xantia S2:

Fan Data:
Number x Electric power2 x 250 W
1st speed97 °C
2nd speed105 °C
Air conditioning cut-off115 °C
Warning118 °C
Post-cooling6 minutes
admiral51
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Re: Xantia 2.0 HDI late model with AC - radiator fans

Post by admiral51 »

The fans will come on if the heater controls are set to demist, however as this is done by putting the A/C on if there is a fault within the A/C system the fans will not spin.
I have just checked my new steed and can confirm that with duff A/C and heater set to demist the fans do not spin.
I have been reading up this issue as i know it is something i need to tackle, this topic last pages has lots of info on the HDI Xantia
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Re: Xantia 2.0 HDI late model with AC - radiator fans

Post by Pshemsky »

Hell Razor5543 wrote:
09 Dec 2018, 15:12
If the a/c is on (or the heater controls are set to demist the windscreen) the fans WILL be on. When the demist option is on the a/c is on (stealthily; the a/c light is not on), as it helps to dry the air coming into the vehicle. This happens on demist even if you have NOT turned on the a/c yourself.

That's interesting James. So when air blow will be directed (for example) towards feet and engine temperature will not reach certain level (not sure what - maybe 95 degrees?) fans should not operate at all ? And opposite situation - when AC is on and blow direction set on screen (demist) both fan should start to operate? And what speed they should reach - slow or full ?
MikeT wrote:
09 Dec 2018, 15:27
What I do is disconnect the coolant temp sensor with engine running as this should cause a cooling fail-safe mode wherein both fans should start, at slow speed briefly before quickly ramping up to full speed - so if you try this don't dangle anything near the blades! If one fan fails to work, the electricals need troubleshooting.

Mike, sorry for being pain in a..., but can have some directions regrding coolant temp sensor location ? :roll:
GiveMeABreak wrote:
09 Dec 2018, 16:03
For the Series Xantia S2:

Fan Data:
Number x Electric power2 x 250 W
1st speed97 °C
2nd speed105 °C
Air conditioning cut-off115 °C
Warning118 °C
Post-cooling6 minutes

Thanks for info. But TBH I don't recall any moment when temperature goes anywhere nerby 97 :/
admiral51 wrote:
09 Dec 2018, 16:17
The fans will come on if the heater controls are set to demist, however as this is done by putting the A/C on if there is a fault within the A/C system the fans will not spin.
I have just checked my new steed and can confirm that with duff A/C and heater set to demist the fans do not spin.
I have been reading up this issue as i know it is something i need to tackle, this topic last pages has lots of info on the HDI Xantia

So when AC+demist on both fans should spin at same speed right ? (slow/high ?)
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Re: Xantia 2.0 HDI late model with AC - radiator fans

Post by GiveMeABreak »

The radiator fans won't come on until temperature reaches 97 °C., unless the A/C has been switched on, which will normally engage the fan at the first speed to cool the compressor.

Only when the temperature hits 105 °C does the second speed kick in.

This data is from the Xantia S2 Data on the A/C circuit.
The controls on the dashboard only operate the A/C - either manually or with demist on - but that just operates the A/C - which in turn operates the Fan as said above.
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Re: Xantia 2.0 HDI late model with AC - radiator fans

Post by MikeT »

Pshemsky wrote:
09 Dec 2018, 16:24
MikeT wrote:
09 Dec 2018, 15:27
What I do is disconnect the coolant temp sensor with engine running as this should cause a cooling fail-safe mode wherein both fans should start, at slow speed briefly before quickly ramping up to full speed - so if you try this don't dangle anything near the blades! If one fan fails to work, the electricals need troubleshooting.

Mike, sorry for being pain in a..., but can have some directions regrding coolant temp sensor location ? :roll:
Not certain but would look around the thermostat housing area. There may be two - one for the temp gauge and one for the ECU. Possibly Green and Blue connectors. Haynes manual should help if you have one?
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Re: Xantia 2.0 HDI late model with AC - radiator fans

Post by GiveMeABreak »

Does this help? Assumed 110 HDi DW10ATED.
Xantia Water Temp Sensor.PNG
7 is the Engine Water Thermostat
9 is the water temp sensor
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Pshemsky
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Re: Xantia 2.0 HDI late model with AC - radiator fans

Post by Pshemsky »

Yes Marc - perfect. I'll check it when rain stop for few minutes :)

------ and the rain had stopped :)

So after removing a sensor only one fan (drivers side) start spining and as Mike said - slowly, then went for full blast.
Unfortunately only one, so there's a problem with second one... any recommendations what (and in which order should be checked) ?
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Re: Xantia 2.0 HDI late model with AC - radiator fans

Post by Hell Razor5543 »

GiveMeABreak wrote:
09 Dec 2018, 15:59
Hell Razor5543 wrote:
09 Dec 2018, 15:12
If the a/c is on (or the heater controls are set to demist the windscreen) the fans WILL be on. When the demist option is on the a/c is on (stealthily; the a/c light is not on), as it helps to dry the air coming into the vehicle. This happens on demits even if you have NOT turned on the a/c yourself.
I think he's on about radiator fans not heater fans James.

I am on about the radiator fans. As the A/C puts a heavier load onto the engine I believe that this will automatically kick on the fans. I KNOW it does on the Xantia, and I believe it does the same for the C5.
Last edited by Hell Razor5543 on 09 Dec 2018, 21:29, edited 2 times in total.
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myglaren
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Re: Xantia 2.0 HDI late model with AC - radiator fans

Post by myglaren »

I think it is actually to cool the aircon radiator, rather than the system radiator.
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Re: Xantia 2.0 HDI late model with AC - radiator fans

Post by MikeT »

Pshemsky wrote:
09 Dec 2018, 16:51
... any recommendations what (and in which order should be checked) ?


Time to get the wiring diagram out and decide where you'd like to start. I think the most common faults revolve around the relays and their circuits.
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Re: Xantia 2.0 HDI late model with AC - radiator fans

Post by admiral51 »

According to the info in the post i linked to both should spin full speed when that sensor plug is removed.
I would be inclined to remove the fan that does not work and apply 12v directly to it, that will determine if the fan itself is at fault and as you have spares it should only cost time and effort, be aware that 12v will set it on full speed so keep fingers well away from the blades.
Can i ask if your aircon is working, does the compressor kick in and if so do you get both fans spinning at slow speed.?
I am used to the MK1 Xantia fan problem so as i now have a MK2 with issues i am keeping a close eye on this thread