V6 Xantia Cooling Fans !!HELP!! **Please**

Unread post by **DHallworth** » 31 Mar 2007, 12:23

Ok.....

Firstly many thanks to all who helped with my cruise control

Biggest problem now is that the cooling fans dont seem to be kicking in!!

Found a melted relay between the two fans at the front, replaced the socket, and put a new relay in thinking it'd be ok.

I shorted the relay out momentarily and the fans kicked in, so i know its not the motors, but when the car gets hot they arent kicking in.

It gets frighteningly hot in traffic

and i would like these fixed ASAP.

Regards
David.

Unread post by **CitroJim** » 31 Mar 2007, 13:01

Hi David,

It all sounds like BITRON problems to me. If you disconnect the (brown) BITRON sensor, the fans should run at top speed and if you put the aircon on the fans should run half-speed irrespective of engine tempertaure.

There have been loads of past posts on these problems and the usual problem is dodgy connections on the BITRON controller ECU which, on most Xantias, hides down under the front nearside headlamp.

Clogzz has posted some useful circuit diaframs of the colling fan electrical wiring in the Aircon section of this forum.

Unread post by **DHallworth** » 31 Mar 2007, 13:11

anybody got any ideas on where this sensor is on the V6 Xantias?

thanks for your reply jim!

David.

Unread post by **CitroJim** » 31 Mar 2007, 13:31

Ahh, now I've seen a post saying where it is. One of the sensors is on a pipe between the cylinder banks but for the life of me I cannot find it now.

If it is not there then it'll be somewhere near the thermostat housing I guess.

As a rough guide, usually, the BITRON is brown, the ECU Coolant Temperature Sensor is green and the Coolant Over-temperature Warning Light Sensor is blue and they'll all be on the top part of the cooling circuit to get the readings from the hottest flow of coolant.

Clogzz · Unread post by **Clogzz** » 31 Mar 2007, 13:33

Just seeing this, quick reply for now, will be back, and beware of overheating the engine.
The brown sensor is on the thermostat housing on all cars.

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

http://www.frenchcarforum.co.uk/forum/v ... hp?t=18871

http://www.frenchcarforum.co.uk/forum/v ... hp?t=14682

http://www.frenchcarforum.co.uk/forum/v ... hp?t=18965

http://www.frenchcarforum.co.uk/forum/v ... hp?t=19090

http://www.frenchcarforum.co.uk/forum/v ... hp?t=19296

Unread post by **xantia_v6** » 31 Mar 2007, 14:40

The bitron sensor on the V6 is not easy to get to. I think that you probably need to remove the thottle body to get to it, but I am not sure because it is a couple of years since I went that far in (when replacing the spark plugs which requires the manifold to come off).

The fans should come on at half speed when the A/C is turned on, regardless of the Bitron sensor, so if they are not coming on at all, then the sensor is not your (only?) problem.

The fans tend to get stiff through under-lubrication, and then they draw a lot more current than they should, which may explain your burnt relay. Check that the fans will spin for at least a few turns if you flick the blades by hand.

After that, you will need to check the votages around the relays and work backwards from there.

Unread post by **DHallworth** » 31 Mar 2007, 15:07

i thought that about the air con aswell.

But then i checked a few other cars in the drive.

Dads 03 Plate V6 406 coupe, my sisters 03 plate 307 and my brothers 01 plate 306, and when turning the air con on, the fans didnt come on on any of them!!

But it does on my XM :S

David.

Clogzz · Unread post by **Clogzz** » 31 Mar 2007, 15:18

How cold is it there now ?
The aircon is only meant to come on at something like 5ºC.
Not a precision sensing, and the XM may sit in the warm patch.
That’s unless the compressors kicked in without fans, in which case we have fan faults.
If shorting out the relay started the fans, you could do that for now to protect the engine from overheating.

Unread post by **DHallworth** » 31 Mar 2007, 15:33

on all three cars the compressor kicked in and the fans stayed off.

On the Xm, although the air con is dead, the fans do come on.

On the Xantia the fans dont come on, but the air con compressor does click as it kicks in.

Up here today its 15 degrees, and the xantias fans still dont come on with the air con, not had a chance to check any of the others though.

David.

Clogzz · Unread post by **Clogzz** » 31 Mar 2007, 16:19

Obviously fan or fan switching faults, except for the XM.
Starting place would be the permanent supply on pin 1 of the coil of the so-called ‘left fan relay’, also referred to as ‘low speed relay’.
That relay only energised must turn both fans on at the low speed.
Back tomorrow.

f00lzz · Unread post by **f00lzz** » 31 Mar 2007, 21:15

Fans definately should cut in when A/C is switched on (few seconds delay)

Unread post by **DHallworth** » 31 Mar 2007, 21:15

well..... had a bit of a fiddle and am now in more of a mess then i was when the fans didnt work!!!!

Took the airbox out, and managed to disconnect the brown bitron sensor.

The fan on the nearside came on full speed, but the other didnt move!!

After having a fiddle and decided to leave it off so that at least one fan was running, put everything back togethor, and now the car wont start!! At all!!

It'll turn over no problem at all, but nothing else happens!! Its not even trying to fire!!

tried fiddling with the imobiliser, being a series 2 theres no codepad, so just locked it and unlocked it a few times.

still nothing.

disconnected the battery for around 20 minutes, incase a sensor we'd messed with upset the ECU.

Still nothing.

At the moment i have a rather expensive lounge on wheels that is marooned on the lawn round the back of the house!!

Any suggestions more then welcomed!!

Thanks in advance guys!!

and a big thanks to cloggz for his input earlier on today!

David

Mandrake · Unread post by **Mandrake** » 31 Mar 2007, 22:36

Hi Dave,

Just on the off chance.... try unplugging the big connector on the Engine ECU (with the battery disconnected first of course) and giving the contacts a good spray/clean with contact cleaner.

I had a similar problem where I was working on the cambelt on my 2.0i and I had tugged on the wiring loom a bit (nothing too rough I thought) and later on when I had everything back together it wouldn't start.

It was turning over but making no attempt to fire....

Took me about half an hour of retracing my steps and checking everything I'd been near before I decided to check the ECU (which I hadn't even taken out of the box) and discovered a bit of corrosion on a few of the contacts. I cleaned the contacts with LPS1 and plugged the plug in and out a few times, put it together, and it started instantly and has been going fine for 3 months now

Worth checking anyway. I don't know where the ECU is on the V6, but on the 2.0i its not far from the radiator filler, so my guess is a bit of coolant got spilt into the ECU box somehow some time in the past (even though the box should protect it) and promoted some corrosion of the contacts, and even just a bit of gentle tugging on the wiring loom was enough to cause the poor contact to manifest itself.

The same could be said of the plugs on all the sensors too - I'd be going around all the visible ECU sensor and actuator plugs around the engine and giving them a dose of the same contact cleaner.

Regards,
Simon

Unread post by **xantia_v6** » 31 Mar 2007, 22:38

Can you isolate it to being lack of ignition or lack of fuel?
Mine has actually flooded a couple of times after playing aound with the electics with the ignition turned on, and made no effort to fire until cranked for about 30 seconds with the throttle floored.

Re the fans, if only one is turning, then the fault depends on whether the controller is trying to run them at half or full speed. If it is trying to run them at full speed, then the fan that is not turning (or one of the relays) is probably open circuit. If it trying to run them at half speed, then the fan that is not turning is probably just seized and in need of lubrication.

Unread post by **DHallworth** » 01 Apr 2007, 02:03

been out now,

the battery has been unplugged for 4 hours, i cleaned up the contacts on the ECU, and i also had a fiddle with the immobiliser again.

Still nothing, what puzzles me the most is that no matter how long i leave her turning for, theres no smell of petrol around her!!

So i tried holding down the red petrol cut off switch, still nothing.

One thing i did notice though, the S and the Snow Flake for the automatic gearbox are flashing simultaneously whilst trying to start her!!

This simple job of finding the temp sensor for the bitron box has turned into a complete nightmare!!!!

It has got me 100% completely and utterly stumped!!!!
David.

French Car Forum

V6 Xantia Cooling Fans !!HELP!! Please

V6 Xantia Cooling Fans !!HELP!! Please