Xantia A/C

Post your Cit/Peu/Ren air conditioning queries or advice.

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Re: Xantia MK2 odd Stop/Temperature dash warning

Post by RichardW »

Usually indicative of the rad fans having failed - they should come on with the AC, so if the AC is switched on (which includes putting the screen on demist...) And the fans don't come on, it flags the warning.

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Re: Xantia MK2 odd Stop/Temperature dash warning

Post by admiral51 »

Richard the A/C does not work something i have pencilled in for easter week to have a look at. It has never worked since i have the car and i only have 1 fan working when i bridge the air/dryer switch.
The flashing/flicker of the Red dot and Stop light seems to have no set pattern, i can go 2 days with nothing then it happens 3 or 5 times in 20 mins, even comes on when moving or when stationary at lights.
I tend to have the setting on demist 90% of the time so totally confused by it atm :(

Jaf i often get the oil level light flashing if i am parked on a slope left/right not up/down :)

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Re: Xantia MK2 odd Stop/Temperature dash warning

Post by white exec »

Both cooling fans should always operate together, never one at a time.
When AC switched on (and engine running) fans should run at low speed.

If Brown temp sensor is unplugged (IGN on), fans should run slow for a second or so, then switch to fast.
Reset by reconnecting the sensor, then turning IGN off then on.

If only one fan is working, check
- fan isn't actually seized or stiff
- fan maxi fuses (one fuse each)
- the three fan relays (check for dirty contacts; make sure the 5-pin one goes in the correct socket)
Fans can be tested individually by disconnecting, and powering up with 12v (via a 30A fuse).

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Re: Xantia MK2 odd Stop/Temperature dash warning

Post by admiral51 »

Ok so had a thought and decided to check things out :)

I decided to unplug the Blue plug ( side of block behind and below the air filter housing ) with ignition on and no fans running at all :(
So a gentle flick of the R/H fan blade ( not with fingers ;) ) and it sprang into life. Put plug back in and it stopped, so unplugged and it sprang into life without any help needed.
With R/H fan running a couple of gentle flicks on the L/H fan and it kicked into life, then began to slow and speed up again. Another couple of plug unplug sessions made no difference in terms L/H fan kicking but a gentle flick it starts and stays at full speed, no slowing down speeding up like before.

So both fans work albeit one needs a helping hand to get going so both are getting power, i really am hoping i do not need to change them as i remember the pain in removing them in situ in the past, my knuckles still have the scars :).
I think my next place to look at is the relays and the contacts as the fans are getting enough power to keep running, maybe not enough to get started.

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Re: Xantia MK2 odd Stop/Temperature dash warning

Post by admiral51 »

Admins can you move/merge this thread with my Xantia A/C thread in the AirCon section as i think both are going to end up with duplicate posts.
Happy to leave it as is if thats what you feel is best

Colin

Edit Thanks Admins :)
Last edited by admiral51 on 08 Mar 2020, 15:47, edited 1 time in total.

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Re: Xantia A/C

Post by admiral51 »

Forgot to say when both fans were running they were running at full speed, not slow then fast.

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Re: Xantia A/C

Post by white exec »

Needing to flick the fans to get them running suggests either that the are mechanically stiff, or that they are receiving insufficient voltage (current) to get them turning.

To check for stiffness, with everything switched off, try turning the fan VERY GENTLY, and see whether you can detect any noticeable reluctance to move. There should be none, and fan should turn very freely under light pressure.

If moving freely, you should check out the bank of three 'cube' relays that control the fans. Unplug each one (one at a time), clean up the base contacts, and plig in and out several times. Do this for all three. Two of them will have four pins on the base, one will have five. Get the 5-pin one back the the right socket (socket will have 5 wired receptacles); other two don't matter - you can swap them.

Try all that, and let us know what happens. If no improvement, checking will have to go back one further stage to temperature control.

A third possibility is that both fans (unlikely?) have motor brush wear/issues, and are not making decent contact with the motor commutator. To check this, if the fans don't start to rotate when they should, try clonking the motor body with something, and see whether they will then spin up. If they do (and you haven't spun the blade) then that suggests the motors need opening up, and the brushes looking at . . . or the motors replacing. But try the other things above first

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white exec
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Re: Xantia A/C

Post by white exec »

admiral51 wrote:
08 Mar 2020, 15:46
Forgot to say when both fans were running they were running at full speed, not slow then fast.
That suggests problem could well be one of the Relays, not allowing slow speed to operate.
Look at the relays first.

If relays are in a bad state, they can be replaced inexpensively.
All three are standard 12v 30/40A automotive relays, and can be the same 5-pin (changeover) type, in which case it doesn't matter which one goes in which socket.
These relays can be got from almost any motor factor or electronics store.

The three relays are inter-connected, and all contacts must be working for the slow-fast operation to work properly. In slow mode, the fans are connected in series; in fast mode, they are connected in parallel. It's your series operation that isn't working. Chances are, it's the 5-pin (changeover) one that is misbehaving.

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Re: Xantia A/C

Post by admiral51 »

Thanks Chris.
I am not that good with electronics but can muddle along.
As you say the 5 pin relay can be used in any position if all 3 are 5 pin would This be the correct one if i got 3 ?

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Re: Xantia A/C

Post by admiral51 »

I can confirm that both fans have free movement,no sticking when manually trying to move them so 99% sure it is an electrical issue not a mechanical one

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Re: Xantia A/C

Post by admiral51 »

Just posting this MK1 Xantia A/C info as it is everything i know about the Fan and A/C operation.
As has been stated in previous posts in this thread the MK2 uses the same fan set up but the Bitron is not used, it is done via a separate ECU.
Just trying to keep everything in one place, those that are not members may not be able to access the link and links within it as i believe some are Members only access

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white exec
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Re: Xantia A/C

Post by white exec »

admiral51 wrote:
08 Mar 2020, 16:23
Thanks Chris.
I am not that good with electronics but can muddle along.
As you say the 5 pin relay can be used in any position if all 3 are 5 pin would This be the correct one if i got 3 ?
That 5-pin relay will be fine, in all three locations.

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Re: Xantia A/C

Post by xantia_v6 »

I would have to say that a fan motor that starts with a spin has worn out brushes. Spinning the fan isn't going to fix a faulty relay or corroded wiring.

I know that the fan motors are difficult to change, On some Xantias at least, you can gain a little space by unclipping the radiators and easing them back a few mm, but I am not sure if that works on an HDI.

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Re: Xantia A/C

Post by white exec »

xantia_v6 wrote:
08 Mar 2020, 20:46
I would have to say that a fan motor that starts with a spin has worn out brushes. Spinning the fan isn't going to fix a faulty relay or corroded wiring.
Fans were reported as starting and running ok at full speed, which suggests that
- both fan motors are still operational
- parallel working (high speed) is ok
which leaves series running (low speed) as the fault . . . likely because of a poor relay contact, limiting the current available.

First and easiest suspect must be the relay switching (known problem), and easier than dismantling motors. Failing that cheap and simple check, maybe a lack of slow-speed command from the system, or indeed motor brushes.

That was my reasoning, Mike.

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Re: Xantia A/C

Post by admiral51 »

Thanks Guys i think i am making progress.
Ever the optimist what rating are the fans just incase i need to find a replacement :rofl2: