Weird air/con symptoms.

alan s · Post by **alan s** » 26 Oct 2004, 03:03

A few weeks ago we had a hot day & I turned the climate control on and all was working well. (Xantia 1994/5 VSX)
Stopped to get petrol whereupon, some old bod who looked old enough to be Methusalahs grandad is stuffing around at the bowser, possibly trying to remember if he'd already put petrol in or if that was why he'd stopped there..[V] anyway, while all this was going on, the car sat idling with air/con whirring merrily away when suddenly it all stopped; inside fan, condensor fans and compressor; stone motherless dead.
I turned it all off and a little while later tried it again but same result...nothing, nowt, zilch...dead as a maggot.
A few days later, we get in the car and my son, not knowing about this, hits the switch to auto and sets the temp to a lower setting whereupon the fan inside the car starts up..."ripper" I think, we're back in business....err, no, sorry; no compressor or condensor fan, but the inside circulation fan is working again 100%.
As I have no manual or wiring diagrams (wish they had the resources around for these that they do for the BX) I'm at a bit of a loss as to where to start. Basic tests indicate that the gas charge is still OK and if that has been lost, then it would have to be coincidental to what I believe to be possibly an electrical or electronic peoblem. I've checked all fuses and the mystery part is why did it all die but then only partially come back to life? Circuit breaker or thermister gone open circuit & stayed that way perhaps & if so where is it?
Any suggestions?
Alan S

Stempy · Post by **Stempy** » 26 Oct 2004, 05:01

Could be a problem with the bitron control box or it's temperature sensor (brown connector, the ecu one is green). If you unplug the brown sensor the cooling fans should come on at full speed. I think the control box can shut the system down if it thinks there is a overheating condition.

alan s · Post by **alan s** » 26 Oct 2004, 10:08

Thanks for that.
I just went and had a look at it & found what I suspect is the bi-tron in an enclosure with the ECU. When I unplugged the brown plug to it, the engine stopped and wouldn't restart until it was reconnected. There's a green "Cartier" relay attached to what would appear to be a home made bracket attached to the side of the ECU which was a bit warm but when disconnected didn't seem to make anything perform any different; got any ideas what that might be?
I do hope we haven't had some of our Aussie genius repairers either "improving" the design or bypassing something electronic (as they have a habit of doing). I'm beginning to get a bit nervous now.
I am totally lost on where to find any bloody thing on this car once I get past the dipstick.
Alan S

Stempy · Post by **Stempy** » 26 Oct 2004, 13:19

The brown connector I was talking about is on a temperature sensor which is most probably near to the themostat housing. Xantia's with A/C generally have three temp. sensors, a green one for the ecu, a brown one for the A/C and engine cooling and a blue one for the gauge. Bitron control boxes can vary in position but seem to be commonly placed behind the headlight/front bumper area where they are exposed to the elements and suffer corrosion of the connector, probably not such a problem in warmer parts of the world.

bernie · Post by **bernie** » 26 Oct 2004, 14:30

Alan, the Bitron control box does have Bitron written in the moulding on the front.

alan s · Post by **alan s** » 26 Oct 2004, 15:01

Thanks guys; this is all going to have to happen in slow motion as it's dark here at present, so I'll go look in the morning; when you are all in bed and report back. [:D][:D]
Obviously, I was looking in the wrong place. The brown connector I found (near the green relay) was in a box just inside the RHF mudguard that also had an ECU in it.
Alan S[;)]

bernie · Post by **bernie** » 26 Oct 2004, 15:28

nite nite[:)][:)]

alan s · Post by **alan s** » 26 Oct 2004, 17:29

Orrighty, now if the Bitron is playing up, is it possible for the fans to work due to engine temperature?
I think (?) they have been operating, but when your ears are full of sweat it can be a bit hard to distinguish that noise from outside similar sounds.
........and oh, yeah, nilly forgot; nite, nite Bernie. [}:)][:I]
Alan S [;)][B)]

bernie · Post by **bernie** » 26 Oct 2004, 17:51

I gave a bitron unit to Tom to interrogate.[}:)][}:)]
Hopefully he might have some info on the thing, Tom?

Richard Gallagher · Post by **Richard Gallagher** » 27 Oct 2004, 00:54

Alan, I recently had problems with my latest Xantias aircon/fans, whereby they were not operating on slow speed but the N/S one would operate on full speed.
When looking for the Bitron unit I found it seriously tucked under the N/S/F headlight, to the extent that after removing the headlight access was still very poor due to a panel which is attached to the bumper covering it up. It is held in place by two nuts, one of which I would only be able to gain access to by removing the bumper.......
As Stempy says removing the brown connector should switch the fans onto maximum.
It may also be worth considering the ignition switch as they heater fan is fed directly from there and as a consequence is prone to failure due to the load thereon.

alan s · Post by **alan s** » 27 Oct 2004, 02:24

Richard,
The heater fan (the one inside the car that blows the air through the front vents) is now working OK although initially it also stopped.
The fans in front of the radiator and condensor are the ones not operating nor will the clutch on the compressor snap in although when the air/con is activated at the switch, the engine seems to momentarily sound as though load comes on (without hearing the click of the compressor clutch) which almost immediately goes back to a normal idle, but this may just be the 'idle step up' cutting in to compensate for the load of the compressor if it was operating.
Alan S

tomsheppard · Post by **tomsheppard** » 02 Nov 2004, 17:51

Bitron units are not repairable, containing two pla chips which are software programmed.
As Bernie says, I have one which I've stripped but not destroyed. Have you time to wait for it if I rebuild it and put it in the post?

alan s · Post by **alan s** » 03 Nov 2004, 03:42

<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by tomsheppard</i>

Bitron units are not repairable, containing two pla chips which are software programmed.
As Bernie says, I have one which I've stripped but not destroyed. Have you time to wait for it if I rebuild it and put it in the post?
<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">
Yes thanks Tom.
I've been without air/con for a few months now and as I used to teach truck drivers in Surfers Paradise in the middle of summer in a 1956 De Soto 6 tonner with holes in the floor above the hot exhaust that blew in my face (cab temp around 45 - 50 degrees some days), I'm sure I can survive until it arrives.[:D][:D][:D]
Alan

tomsheppard · Post by **tomsheppard** » 03 Nov 2004, 13:51

OK Alan, Address to
tomattomshepdotcodotuk please and I'll stick it in the post on Saturday when I get home. It was a reward for helping Bernie with his a/c so I'm happy to pass it on to you to thank you for your help with mine!

alan s · Post by **alan s** » 03 Nov 2004, 15:47

Tom,
Did you receive my e-mail with my address included?
Alan S