Xantia Heater Fan

Nigel Darwell · Post by **Nigel Darwell** » 18 Jan 2004, 22:15

I have a Mk2 facelift Xantia (1999), with aircon and the climate (ish) contol. Does any one know how the speed contol circuits work ? I have no activity at all from the fan, although you can hear a faint 'crackling' from the fans onboard electronics when the slider is in any other position than off. I have 12v across the red/black at the fan connector, so assuming NOT a ignition switch problem. Does any one know what the other three thin wires to the fan do ? what voltages should I see on these ? - how should these change when different speeds are being called for ? If you put a 12v feed directly to the fan (bypassing its electronics)fan runs properly. Does anyone know where the ECU is located ?
[|)] (shivering)

AndersDK · Post by **AndersDK** » 18 Jan 2004, 22:56

Nigel - first off try fiddle with the ignition key while the fan is supposed to come on.
The Xantia ignition key switch are reputed to burn out.

PeterMann · Post by **PeterMann** » 19 Jan 2004, 05:20

Recently had to replace the battery in my 1994 Xantia. And while we were swapping old for new, I noticed several earthing points under the battery. So after returning home, I pulled out the battery to clean the newly-discovered suspects in the quest for reliable heater/aircon operation. There are 3 earth points concealed under the battery (the worst possible place in terms of corrosion), and removing the battery allows access to a further 7 earth points immediately behind the battery.
Loosened each of these, inserted some gearbox oil onto the bolt thread and the electrical termination, and tightened up. Heater blower has worked reliably since then.
In retrospect, cleaning these earthing points would be my first move in trying to sort out any electrical malfunction on the Xantia.

AndersDK · Post by **AndersDK** » 19 Jan 2004, 05:23

Peter -
This is really a great TIP [8D]
I don't believe anyone would think the battery should be removed to check this.
Well done mate [^]

Nigel Darwell · Post by **Nigel Darwell** » 19 Jan 2004, 23:31

No luck on the key, but do have 12v at the motor, and think a '99 model may have a relay, can any one confirm ?

davey · Post by **davey** » 20 Jan 2004, 03:20

Ref your fan assy. If it is the same setup as the berlingo with aircon ... then its not quite straightforward.
I found the opposite on the heater fan was happening - it ran constantly regardless of setting. The fan had the same connections as you describe 2 thick power wires and a number of thin ones on a connector block that disappeared inside the blower housing with a separate red and black coming back out for the blower motor.
If you have the same or similar then the motor speed controller may be electronic and incorporated inside the blower housing. Have another look. If possible take out the blower assy (very easy to do on berlingo) and open it up, if there is a board in there with a couple of power trannies on it its electronic control.
If you have this setup give me a shout as I spent hours on it but repaired it in the end.

Nigel Darwell · Post by **Nigel Darwell** » 20 Jan 2004, 21:27

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by davey

Ref your fan assy. If it is the same setup as the berlingo with aircon ... then its not quite straightforward.
I found the opposite on the heater fan was happening - it ran constantly regardless of setting. The fan had the same connections as you describe 2 thick power wires and a number of thin ones on a connector block that disappeared inside the blower housing with a separate red and black coming back out for the blower motor.
If you have the same or similar then the motor speed controller may be electronic and incorporated inside the blower housing. Have another look. If possible take out the blower assy (very easy to do on berlingo) and open it up, if there is a board in there with a couple of power trannies on it its electronic control.
If you have this setup give me a shout as I spent hours on it but repaired it in the end.
<hr height="1" noshade id="quote"></blockquote id="quote">

Nigel Darwell · Post by **Nigel Darwell** » 20 Jan 2004, 21:28

Davey
Yes it sound exactly like the one you describe.
<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by Nigel Darwell

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by davey

Ref your fan assy. If it is the same setup as the berlingo with aircon ... then its not quite straightforward.
I found the opposite on the heater fan was happening - it ran constantly regardless of setting. The fan had the same connections as you describe 2 thick power wires and a number of thin ones on a connector block that disappeared inside the blower housing with a separate red and black coming back out for the blower motor.
If you have the same or similar then the motor speed controller may be electronic and incorporated inside the blower housing. Have another look. If possible take out the blower assy (very easy to do on berlingo) and open it up, if there is a board in there with a couple of power trannies on it its electronic control.
If you have this setup give me a shout as I spent hours on it but repaired it in the end.
<hr height="1" noshade id="quote"></blockquote id="quote">
<hr height="1" noshade id="quote"></blockquote id="quote">

wilsonkrg · Post by **wilsonkrg** » 21 Jan 2004, 17:30

Nigel,
I think this site has the circuit diagram you need.
http://citroeny.cz/servis/xantiaser/klima/klima.htm
The ECU sits on top the the ventilation system just under the fascia - impossible to take out unless you take out the but you might be able to reach it by taking out the glovebox (look under felt in bottom of glove box for holes to get to bottom screws)
If you take out fan it has a big heatsink with 2 big power transistors on it mounted in the housing.
Good Luck
Ken W

David W · Post by **David W** » 21 Jan 2004, 19:31

Before Christmas I had exactly the same symptoms as Nigel on a Xantia I look after.
Investigation found that the motor ran when powered directly, and that the main power feed was good. Due to signs of overheating at the connectors, and in discussion with the local Citroen dealers, it seemed that the electronics pack had failed. Owners decision was to replace the whole fan assy complete with electronic pack as the cost was little more than just the electronics.
I was due to order the part the following day but reassembled the fan etc so they could use the car in the meantime.
Damn me if the fan didn't start working after a couple of miles taking the car back to them, and it is still fine after a month!
David