aircon please help

weety · Post by **weety** » 07 Aug 2006, 18:03

Please help

i have a r reg xantia td with air con and climate control

now ever since i got the car the air con has never worked properly, the internal fan cuts in and out independently of the controls and when it is working the air temprature through the vents bears no relationship to the temprature set on the controls

ie even if you set it to cold it will pump some cold air then hot air then cold air

i have been working on the problem (on and off) for months and i think i have finally worked out whats wrong but wanted to see if anyone else has got any ideas....

ok so far i have put a new internal fan on it (the old one wasnt working properly) and i have changed the ignition switch in case that was why the fan was working intermitantly

the system has been fully regassed and the aircon definately works of the aircon on/off switch

the only thing i can think it is now is the computer it must have to run the climate control....

so.........

does it have just one computer doing this and does anyone know where it is/they are on the car?

as another solution i have considered taking the dash out and trying to manually rig the flaps that must control the air mix from the hot and cold...is this possible? does it have one or two flaps and does anyone know if you can sensibly get at them

i have worked out how i could get the fan to run of a different switch (the fan seems to be permanently live when the ignition is on, it actually works when the live feed is reduced or stopped so that wont be a problem

any help or advice will be greatly appreciated

cheers

h2ocooler · Post by **h2ocooler** » 08 Aug 2006, 00:58

First thing to check is the temp sensor in the dash, its the little grille with the alarm light in it, there is a little fan behind it that draws air through, if the fans not working that will confuse the CC.
Does the main blower fan work now? if it does then check the pollen filter, mine was blocked and hardly any air came out of the vents (when oy u have the filter out you can see the Evap for the AC nexy to where the filter goes, carefully feel it with the AC on and you will know if its getting cold.
IIRC the control flaps on Xantias are moved by servo motors, and the ECU for the AC is the "Bitron" and is under the LH headlamp on the inner wing i think.

weety · Post by **weety** » 08 Aug 2006, 08:52

h2ocooler wrote:First thing to check is the temp sensor in the dash, its the little grille with the alarm light in it, there is a little fan behind it that draws air through, if the fans not working that will confuse the CC.
Does the main blower fan work now? if it does then check the pollen filter, mine was blocked and hardly any air came out of the vents (when oy u have the filter out you can see the Evap for the AC nexy to where the filter goes, carefully feel it with the AC on and you will know if its getting cold.
IIRC the control flaps on Xantias are moved by servo motors, and the ECU for the AC is the "Bitron" and is under the LH headlamp on the inner wing i think.

the temp sensor works (its another thing that i replaced),

the main blower fan only works when it feels like it,

i have changed the pollen filter (which wasnt blocked anyway) i will tug the filter out and check the evap (though it does blow cold air sometimes anyway)

havent changed the bitron yet (i suppose that should be my next step)

Clogzz · Post by **Clogzz** » 08 Aug 2006, 14:47

The Bitron is to control the engine cooling fans.
Blower fan stopping is usually caused by the ignition switch.
Story here:

http://www.frenchcarforum.co.uk/forum/v ... hp?t=17322

weety · Post by **weety** » 08 Aug 2006, 18:01

Clogzz wrote:The Bitron is to control the engine cooling fans.
Blower fan stopping is usually caused by the ignition switch.
Story here:

http://www.frenchcarforum.co.uk/forum/v ... hp?t=17322

yeah i had heard about that fault and i put a new ignition barrel on anyway so its definately not that (heated rear window works fine anyway).....

alan s · Post by **alan s** » 08 Aug 2006, 23:11

weety wrote:
Clogzz wrote:The Bitron is to control the engine cooling fans.
Blower fan stopping is usually caused by the ignition switch.
Story here:

http://www.frenchcarforum.co.uk/forum/v ... hp?t=17322
yeah i had heard about that fault and i put a new ignition barrel on anyway so its definately not that (heated rear window works fine anyway).....

Having had one of these and done the mod, I'd still be inclined to look at doing it if for no other reason than the fact it is going to be a drama eventually anyway at which time it'll take out the new switch possibly.
It may also be the problem if you have degradation internally of the wiring and this may have reached the stage where internal breaks could be involved particularly at places such as where it connects to terminals. Intermittent faults and internal breaks often go hand in hand and wires that have degraded or annealed through heat can easily create these breaks.

Alan S

weety · Post by **weety** » 09 Aug 2006, 08:03

alan s wrote:
weety wrote:
Clogzz wrote:The Bitron is to control the engine cooling fans.
Blower fan stopping is usually caused by the ignition switch.
Story here:

http://www.frenchcarforum.co.uk/forum/v ... hp?t=17322
yeah i had heard about that fault and i put a new ignition barrel on anyway so its definately not that (heated rear window works fine anyway).....
Having had one of these and done the mod, I'd still be inclined to look at doing it if for no other reason than the fact it is going to be a drama eventually anyway at which time it'll take out the new switch possibly.
It may also be the problem if you have degradation internally of the wiring and this may have reached the stage where internal breaks could be involved particularly at places such as where it connects to terminals. Intermittent faults and internal breaks often go hand in hand and wires that have degraded or annealed through heat can easily create these breaks.

Alan S

hadnt thought of that....... i will mod in the relay and see if that helps....

Clogzz · Post by **Clogzz** » 09 Aug 2006, 14:21

Part of the blower motor speed control, and the motorised flap controls are in the climate control ECU, which is to the right of the blower motor, towards the centre of the dash.
Never been there, but ‘BonceChops’ has a post on the subject that I can’t find anymore.
Story from Peugeot, with clickable map:

http://www.peugeotlogic.com/workshop/ws ... /ac405.htm

weety · Post by **weety** » 09 Aug 2006, 15:03

Clogzz wrote:Part of the blower motor speed control, and the motorised flap controls are in the climate control ECU, which is to the right of the blower motor, towards the centre of the dash.
Never been there, but ‘BonceChops’ has a post on the subject that I can’t find anymore.
Story from Peugeot, with clickable map:

http://www.peugeotlogic.com/workshop/ws ... /ac405.htm

thanks thats really useful couldnt find any sort of diagrams myself.....have to say i am considering buying an air con car that works and then swapping parts over.....

did a quick search on autotrader and found a w reg 1.8 xantia for £395 and an old n reg airconned 2 litre for a couple of hundred....does anyone know if the aircon system on the old N reg would be the same as the later ones they were fitting as standard?

they dont seem to have any airconned xantias in teh cheap scrappies round me.....

Clogzz · Post by **Clogzz** » 10 Aug 2006, 13:41

Don’t know to what extent it means differences to the system, but on the Mk II, when you set the slider to demist the windscreen, it automatically turns on the air conditioning.
Found these maps since.

weety · Post by **weety** » 10 Aug 2006, 14:25

Clogzz wrote:Don’t know to what extent it means differences to the system, but on the Mk II, when you set the slider to demist the windscreen, it automatically turns on the air conditioning.
Found these maps since.

strewth just got back from a liquid lunch looked at your plans and thought i had forgotten how to read (which would have been bad)

thanks for those, i will have a look later........ it should help my swap parts over policy

my xantia is mark 1 anyway (just on the change but single airbag etc) so hopefully it will be the same...

no bids on e bay for the xantia i am looking at yet........

weety · Post by **weety** » 13 Aug 2006, 10:29

well the cheap xantia on e bay went for 255 quid (P reg 18 petrol no tax or mot) so i didnt get that

i had another though if i changed the front panel heater control and the 'airbox' to one of a non air conditioned car, then wired in a switch for the fan i should have air con without climate control (ie manually adjustable)....

dont suppose anyone knows if the airboxes are different??

Clogzz · Post by **Clogzz** » 13 Aug 2006, 13:13

The air box is different because the air-conditioned car has the evaporator and pollen filter in it.
Most of all, the climate control board in the dash senses if the fan is spinning before turning on the air conditioning, so you will have to fool that into thinking it’s spinning.

Don’t know to what extent the climate control board is tangled up with the air conditioning system proper, but you’d be embarking on quite some bodgie here, with a lot of map reading needed to work out how to go about it, unless we get to read from people who have done it.

Simplest is still to get the fan to spin consistently.
It's not rocket science; some have done it in about an hour, and at least you will have plenty of company for in case it doesn't go according to plan.

weety · Post by **weety** » 13 Aug 2006, 13:21

Clogzz wrote:The air box is different because the air-conditioned car has the evaporator and pollen filter in it.
Most of all, the climate control board in the dash senses if the fan is spinning before turning on the air conditioning, so you will have to fool that into thinking it’s spinning.

Don’t know to what extent the climate control board is tangled up with the air conditioning system proper, but you’d be embarking on quite some bodgie here, with a lot of map reading needed to work out how to go about it, unless we get to read from people who have done it.

Simplest is still to get the fan to spin consistently.
It's not rocket science; some have done it in about an hour, and at least you will have plenty of company for in case it doesn't go according to plan.

fan is easy there is a live running to it that spins the fan when it goes er less? live or earth.....easy bodge is just to run an earth (i used the cigarette lighter earth) to it through a switch.....fan will then spin at full speed when turned on......

still hoping to get a new (well second hand) air con ecu and hope its just that and not the control cables for the flaps in the airbox.......