Xantia Aircon stuck on!!! HELP!!! BBBBRRRRRRRRRR... COLD!

eskimoigloo · Unread post by **eskimoigloo** » 02 Dec 2005, 14:19

Hi, my aircon has decided to be permanently on whether the switch on the dash is or not! This also means that the 2 fans are on slow speed all of the time! Apart from being cold I am worried about the constant wear on all of the pump/fans etc. and my reduced fuel economy. I took the fuse out in the dash to stop it, but then realised this also stops the blower working... DOH! What's the most likely culprit??? relay? switch? Where is the relay?
Any urgent help appreciated in this already cold weather!

ps. It's a 2001 Xantia HDi

Chris.

Clogzz · Unread post by **Clogzz** » 02 Dec 2005, 14:41

The aircon switch on the dash may cause that.
Try prising it out to pull the connector off.
Taking out the connector to the compressor clutch will stop the compressor from working, but that won't stop the cooling fans from spinning, because they are controlled by the Bitron fan control box which gets its input from the dash switch.

eskimoigloo · Unread post by **eskimoigloo** » 02 Dec 2005, 14:48

So there are no relays... it's just this dreaded bitron unit thingy or the switch?

Chris

Clogzz · Unread post by **Clogzz** » 02 Dec 2005, 15:07

There's no relay to operate the air conditioning that I'm aware of.
It does have the solenoid to engage the clutch on the compressor.
There are relays to operate the cooling fans, but they're working normally since the low speed is on.
The Bitron is inside the fuse box under the bonnet, and the usual fault is oxidised terminals that need a good scrape.
I've got posts on the subject, but can't find them now.

Here is the map for the fans:

http://www.frenchcarforum.co.uk/forum/v ... hp?t=17012

And here is the air conditioning forum:

http://www.frenchcarforum.co.uk/forum/v ... 16943bcf59

eskimoigloo · Unread post by **eskimoigloo** » 02 Dec 2005, 15:09

Hi, pulled the switch, and it went off! So that's that sorted cheers!

Chris.

drpau · Unread post by **drpau** » 02 Dec 2005, 15:38

WHich 'direction' have you got the blowers set to? I know that on my Xsara if you set it to the windscreen it automatically uses aircon as this is the best way to demist. If you use a different setting it wont switch the A/C on unless you press the A/c button.

Mandrake · Unread post by **Mandrake** » 02 Dec 2005, 19:31

Clogzz wrote:There's no relay to operate the air conditioning that I'm aware of.
It does have the solenoid to engage the clutch on the compressor.
There are relays to operate the cooling fans, but they're working normally since the low speed is on.

Actually I think there must be a relay involved in the later models - because on my 1997 there is about a 3 second delay from pushing the button until the "click" of the clutch solenoid.

On the other hand my mums 1993, and Dad's 1994 both click immediately with the button.

I'm guessing they added a delay to prevent the compressor from loading the engine during starting.

Now, if only I could find where it is, as it may be the reason why my compressor clutch sometimes wont turn on...

Regards,
Simon

np · Unread post by np » 02 Dec 2005, 19:44

My Xantia has a delay as well.About 3-5 secs before the compressor engages after pressing the button.Mines a late 97 "mk 1" pre face lift.
DO`H!!

As you can see from the photo

Clogzz · Unread post by **Clogzz** » 04 Dec 2005, 10:49

Mandrake wrote: Actually I think there must be a relay involved in the later models - because on my 1997 there is about a 3 second delay from pushing the button until the "click" of the clutch solenoid.

Looks likely, there's definitely something, and I think that the Haynes book says that it's controlled by the ECU.
My 1995 Xantia sometimes takes about 5 seconds to engage the clutch.
When you set the fan speed control to 'off', the air con won't work either, so that one knows about it too.