Xantia 2.0 Petrol Fan constantly comes on

chesterkeff · Unread post by **chesterkeff** » 30 Jun 2011, 21:26

Hello long time no visit.

Problem arising with fan on the Xantia. Keeps coming on and off even after cold start up and very short journey. Any ideas. Fan very loud, or at least it seems that way to me. Anyone had similar problem?

Many thanks for your help

Unread post by **CitroJim** » 30 Jun 2011, 21:33

This can happen if the aircon is switched on all the time...

The more likely cause though is the Bitron temperature sensor having gone open-circuit or the connection to it is bad.

The Bitron sensor will be found screwed into the thermostat housing and it's brown coloured. There will be two other nearby; a green and a blue one.

Check the connection to the Bitron. With it disconnected the fans will run at top-speed constantly as a fail-safe against the sensor failing.

Clean and reseat the connector as a first check.

chesterkeff · Unread post by **chesterkeff** » 30 Jun 2011, 21:45

Many thanks will check it out.

jmd · Unread post by **jmd** » 01 Jul 2011, 01:44

Check also -Is the heater control switch set to the ''demister position'' this automatically engages the air conditioning, even if the normal air-conditioning switch is set to off. This would engage the fans & make them cut on & off, and is normal.

Unread post by **RichardW** » 01 Jul 2011, 07:37

jmd wrote: This would engage the fans & make them cut on & off, and is normal.

Not quite....both should run continuously at slow speed with the AC running.... if one is coming on and off at high speed when AC is on then chances are the other one is knackered and hence they won't run in parallel (ie slow speed)