Fitting Air Conditioning.

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David
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Fitting Air Conditioning.

Post by David »

Hi all, I have recently acquired an air conditioning system for my BX. Already I have a few questions on how to put it all in.

The car is all in bits; the dash and heater are out and scuttle compartment is all in bits, and I have made a start on cutting the extra holes for the pipes and recirculation flaps.

So the questions are;

-I am planning on using R134a gas, I have already asked someone who can charge the system about using this in a R12 system, but he says it just vacs down, removing all the oil and air, then he would just recharge it with new oil & gas. He also says that the R12 seals would be compatible.

But I am sure I have read on here (somewhere) that all the seals need changing and that all the oil needs manually removing. Can anyone confirm of deny if any of this is correct? If its the latter, how would I go about removing all the oil? Also, would standard oil seals be up to the job or do I need special seals?

-All the wires are missing for the system. I think I can work most of it out, although I am not really worrying about the wires yet, But what is the black box for that is on the heater, just under/ behind the control panel?
How do the recirculation flaps work?
Also are the 2 heater blower fans just connected together in parallel, or is it more complicated than that?

I have already got a new drier and heater matrix for it while everything is out.

I'm sure I will have more questions, But I will be back with them as I come across them.

Any help would be greatly appreciated.
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Re: Fitting Air Conditioning.

Post by Vanny »

In the absence of a WYSIWYG editor, i have replied to your message in blue
David wrote:Hi all, I have recently acquired an air conditioning system for my BX. Already I have a few questions on how to put it all in.

The car is all in bits; the dash and heater are out and scuttle compartment is all in bits, and I have made a start on cutting the extra holes for the pipes and recirculation flaps.

So the questions are;

-I am planning on using R134a gas, I have already asked someone who can charge the system about using this in a R12 system, but he says it just vacs down, removing all the oil and air, then he would just recharge it with new oil & gas. He also says that the R12 seals would be compatible.

Find someone who knows what they are doing for a start. Drawing the vacuum will remove existing gas and so long as the vacuum is low enough (2torr) and its a warm day, all the moisture will boil off. This is the important bit.

R12 seals are compatible when they are NEW but not when they have come from an old BX or if they have been allowed to go dry (ie the system has been opened and air let in). In the case of a transplant, the seals are useless. A full kit of seals is available from Citroen with the correct neoprene seals (its generic with more seals than you need) for about £14. You can buy a box of seals from Autoclimate with hundreds of the correct type and sizes for a little bit more.

Realistically you will probably need adapters to take the charge port from R12 fitting to R134a fitting, these are about £4, you only need one as the BX system only really has a high pressure charge port


But I am sure I have read on here (somewhere) that all the seals need changing and that all the oil needs manually removing. Can anyone confirm of deny if any of this is correct? If its the latter, how would I go about removing all the oil? Also, would standard oil seals be up to the job or do I need special seals?

Opinion on oil is divided. R12 and R134a oils are different, but in reality they are there to protect the pump, keep the seals supple and extand the life of the pipes. If your fitting new seals and R134a gas, you might as well clean the old oil out and put some new oil in. You can buy drop in oils which are compatible with both, but if your cleaning the pipes out anyway, and the compressor, then use new oil.

Cleaning oil out of pipes is straight forward, flush each one with white spirit (I was told this by an old boy AC engineer, but accept no responsibility etc). I use an old fuel pump for this purpose. After a while the white spirit will become a little yellowed with the oil. Chemical such as petrol will damage the pipe liner.

Cleaning out the compressor is a little harder if you don't have a machine. Search the internet for the Sanden compressor manual which will give you an idea how to do it. I would argue that a little old oil left in wont hurt.


-All the wires are missing for the system. I think I can work most of it out, although I am not really worrying about the wires yet,

But what is the black box for that is on the heater, just under/ behind the control panel?

Compressor control

How do the recirculation flaps work?

There are units that clip onto the hvac blower intake with a door to select fresh air and cabin air (through a hole in the bulk head). Its worth checking that your shell was made with these holes or you have a lot of work ahead of you. A servo move the door position based on a potentiometer on the back of the AC control panel.

Also are the 2 heater blower fans just connected together in parallel, or is it more complicated than that?

Its a pretty simple arrangement, have a look at the wiring diagram

I have already got a new drier and heater matrix for it while everything is out.

I'm sure I will have more questions, But I will be back with them as I come across them.

Have a good old search on here as the topic has been covered a few times (although never completely).

Any help would be greatly appreciated.
There are two types of wiring harness for factory fit air con. I refer to them as 16v and diesel (because that is where i got the looms and what the wiring diagrams are called. The 16v is different in that it can put power to the compressor if the ECU requests it (based on throttle position). There are also 'cold market' variants.

There are at least two types of AC. Aftermarket and factory fit (its worth noting that the Mk1 all use the aftermarket kit, even when fitted in the factory). Aftermarket kits have a single snow flake button but the hand brake, factory kit has the new control panel and other features.

You have mentioned it but you MUST have the dual fan system setup in order to keep system pressure down (and efficiency up).

Have a look on the BXProject and there are numerous articles, galleries and technical details including the period correct Citroen AC manual.
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Re: Fitting Air Conditioning.

Post by David »

Thanks for the reply. The car didn't have the holes in for the system, I have now cut them in. This system like like it was a factory fitted original, I have also got all new seals for everything. But I have come across more problems.

I came to swapping the sump today and the spacer and alloy sump won't go on because of the flywheel, it touches the sump and spacer, stopping them from going on. So the question is, what can I do to make it fit? The only solutions I have thought of are change the flywheel for a different one, have mine machined out by an engineering works or cut the sump down, but I am concerned this would leak oil. Any suggestions? My flywheel is a standard 1.7 none turbo diesel one, with the smaller clutch.

Also on the new heater matrix I have got, the pipes are at a slightly different angle, but it makes a noticeable difference by the time they get to the tap. It is about 1-1.5cm and about 2-2.5cm by the time it goes to the bulkhead, So what can I do about this?

Also will any old oil on the system actually do any damage? I have removed the loose oil in the radiators and pipes, and i have blown compressed air through the pipes, but I have not cleaned it any further.

And where is (are) the charge port(s) for the system? I have found a valve in the pipe, near the compressor that looks like one, and there are 2 valves in the actual compressor, but I don't know what these are.

Any more help would be greatly appreciated.
1992 Citroën BX 1.9 Diesel Meteor 4x4 - The Project.

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Re: Fitting Air Conditioning.

Post by djoptix »

I have a 16v with factory aircon which you're welcome to come and have a look at if it helps. It isn't working, but might help you find out where stuff is.

It's in Herefordshire just off the end of the M50, so it's miles from you, but only about half an hour off the M5 if you find yourself heading South. PM me if it's ever of interest.
Good heavens! My signature's been moderated...
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Re: Fitting Air Conditioning.

Post by Vanny »

Again, my replies are in BLUE
David wrote:Thanks for the reply. The car didn't have the holes in for the system, I have now cut them in. This system like like it was a factory fitted original, I have also got all new seals for everything. But I have come across more problems.

I came to swapping the sump today and the spacer and alloy sump won't go on because of the flywheel, it touches the sump and spacer, stopping them from going on. So the question is, what can I do to make it fit? The only solutions I have thought of are change the flywheel for a different one, have mine machined out by an engineering works or cut the sump down, but I am concerned this would leak oil. Any suggestions? My flywheel is a standard 1.7 none turbo diesel one, with the smaller clutch.

A picture might help to explain what you mean as i'm not 100% sure i grasp the problem. However to my knowledge (and someone with more experience should be able to help) you do not fit the spacer when fitting the alloy sump.

Also on the new heater matrix I have got, the pipes are at a slightly different angle, but it makes a noticeable difference by the time they get to the tap. It is about 1-1.5cm and about 2-2.5cm by the time it goes to the bulkhead, So what can I do about this?

All Mk2 heater matrix are the same, so the obvious question, is it the right part. I wonder if you are worrying about nothing? The tap goes through the big rubber seal and connects to big rubber pipes with funny angles. There is plenty of free play, equally when you take the heater matrix off the tap, the weight and tension in the pipes would normally cause the tap to move upwards. Can they be made the align with gentle pressure (it dont snap the pipes in the engine side)

Also will any old oil on the system actually do any damage? I have removed the loose oil in the radiators and pipes, and i have blown compressed air through the pipes, but I have not cleaned it any further.

Its a very good question, and not one I have ever managed to get a detailed answer to. All professionals and professional bodies say it must be changed. They are very different oils PAG Vs POE. But no one has ever been able to tell me the implications of not doing it. Realistically, flushing out is easy enough on the pipes, and you can pour most of it out of the compressor. Personally i would flush the lot out and change the oil.

And where is (are) the charge port(s) for the system? I have found a valve in the pipe, near the compressor that looks like one, and there are 2 valves in the actual compressor, but I don't know what these are.

As mentioned the BX only has one proper charge port, the one on the pipe you have found. The second port is ONE of the caps on the compressor, which needs an adapter, which i've never tracked down (but is apparently common). You only really need one port to charge, so long as your not using an all in one machine.

Any more help would be greatly appreciated.
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Re: Fitting Air Conditioning.

Post by David »

Thanks again for the replies.

I am hoping I can put it together without looking at another car for reference, But thanks for the offer if needed.

I can't get any pictures to upload on here, since the server was changed, But I will try to explain what the problem is; The sump and spacer are touching the flywheel. It won't even line up with most of the bolt holes because the flywheel is in the way. I have looked at the GTi flywheel in the shed (which is cracked and useless) and it has an extra groove in the back for the sump and spacer to sit in.

It needs the spacer on this as the sump won't go up to the engine without. It hits the oil pump, and when I sat the 2 sumps together, the alloy one is actually smaller thst the other, but with the spacer they are the same size. I have already got the longer bolts to fit.

The heater matrix is an after market one and not a factory original, so that could be the answer there. The complete heater and tap are all out of the car. I have bolted the tap to the matrix, but when the matrix is in the heater where it should be, the pipes are away, as described above. So what can I do here?
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Re: Fitting Air Conditioning.

Post by Jaba »

David wrote:Thanks again for the replies.

I am hoping I can put it together without looking at another car for reference, But thanks for the offer if needed.

I can't get any pictures to upload on here, since the server was changed, But I will try to explain what the problem is; The sump and spacer are touching the flywheel. It won't even line up with most of the bolt holes because the flywheel is in the way. I have looked at the GTi flywheel in the shed (which is cracked and useless) and it has an extra groove in the back for the sump and spacer to sit in.

I think you have two options here : Grind the sump end so that it clears the flywheel - as long as you have at least the width of the main bearing cap left you will be able to get a seal using silicone.Or fit another more suitable flywheel

It needs the spacer on this as the sump won't go up to the engine without. It hits the oil pump, and when I sat the 2 sumps together, the alloy one is actually smaller thst the other, but with the spacer they are the same size. I have already got the longer bolts to fit.

You sometimes have to cut the spacer ribs to clear the dipstick tube.

The heater matrix is an after market one and not a factory original, so that could be the answer there. The complete heater and tap are all out of the car. I have bolted the tap to the matrix, but when the matrix is in the heater where it should be, the pipes are away, as described above. So what can I do here?

Easiest solution might be to swap in another standard heater matrix. But it must have worked on the donor car so maybe you will be able to get the two engine hoses on without straining them.
As far as the oil issue goes the R12 mineral oil is not compatible with either PAG oil or R134a refrigerant. However Ester oil is with both as well as PAG oil too.
What I have done at conversion time is to use only ester oil, this then mixes up with the old oil residues and does the job. Then when it needs a recharge I get the ester oil blend removed ( well as much as will come out) then let them put PAG oil in which is compatible with ester oil. This procedure has worked on both my BXs.
I don't think the aircon trade did any of this when they did an R12 conversion to R134a. They simply vacuumed out and put PAG oil in.
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Re: Fitting Air Conditioning.

Post by David »

Hi again, thanks for the reply. I have been busy today with the car and have got yet more questions.

With regards to the oil, the best solution would be to use ester oil and have it gassed with R134a without oil then? Where would I get the oil from and how much would it need?

I have managed to get around the heater matrix problem, and today have put most of the a/c system in & most of the car back together.
I just bent the control rods going to the heater tap slightly, and give the heater a good push until the pipes and bolt holes all lined up and went in their holes. The AC pipes coming out of the heater, surprisingly, went in very easily.
The heater matrix is brand new, but its an after market one, and not a factory original.

I have not sorted the sump problem yet, but I have currently got the compressor tied in front of the engine with some rope, and all the ac pipes are loosely assembled on the car.

I have had a quick search on here, but can't find anything regarding wiring, so, how do I wire everything up? I have had a look at everything, but can't understand how it all wires together. There are 2 plugs coming from the heater, one with 3 black wires in it & another with 6 different coloured wires in it.
It is mainly the recirculation flaps I can't understand, as there are 6 wires coming off the switch, (3 for each side I assume) and 2 off each motor, but there seems to be nothing electronically to stop the motors trying to turn too far, thus by my understanding, trying to burn them out. is there something simple I am missing here?

Also, the actual AC switch does not seem to be a straight forward switch, but a variable switch, like the heater fan switch, which then connects to the black box on the heater itself (Which I have already been told is the compressor controller).

Does anyone have any (simple) wiring diagrams of how to wire it up, or any suggestions? I have thought about forgetting the original wiring and doing it my own way, but I would not be able to use the proper AC panel and switches if I do that.

Thanks again in advance.
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Re: Fitting Air Conditioning.

Post by Vanny »

Have a word with these guys;

https://www.koolairconsupplies.com/

They gave me a lot of tuition on how to convert the BX system and have all the components you will need.

The wiring is very simple, and not as confusing as it first appears. As mentioned above, you need to figure out which harness you have and which diagram to follow. The diagrams can all be found on the BXProject.

I dont think there is a simpler way to wire it up than the original, so it would be well worth having a good look before trying to reinvent the wheel so to speak.
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Re: Fitting Air Conditioning.

Post by Jaba »

David wrote: With regards to the oil, the best solution would be to use ester oil and have it gassed with R134a without oil then? Where would I get the oil from and how much would it need?

You can get it from the place that Vanny suggested. I forget how much you need , its about 140cc I think. If you download the Sanden 715 service manual this will help you.Just drain out whatever oil there is in the compressor and then put the new oil in. The system could do with a good flush really and a good long vacuum before recharging.



Also, the actual AC switch does not seem to be a straight forward switch, but a variable switch, like the heater fan switch, which then connects to the black box on the heater itself (Which I have already been told is the compressor controller).

Its a clever way of varying the amount of cooling the aircon produces.

Does anyone have any (simple) wiring diagrams of how to wire it up, or any suggestions? I have thought about forgetting the original wiring and doing it my own way, but I would not be able to use the proper AC panel and switches if I do that.

I have wiring diagrams if the Vanny's BX project does not provide what you need.

Thanks again in advance.
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Re: Fitting Air Conditioning.

Post by David »

Thanks again for the replies. I have looked on the bx project site, and found a topic in fitting ac, but the pictures have gone, including the diagrams. Would it be possible for anyone to post them in here, or send me the diagram directly? Also, I am struggling to see where the pipes go around the air filter unit, could anyone possibly send me a picture of where the pipes and drier fit?
Thanks again in advance.
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1992 Citroën BX 1.9 TXD (with GTI engine; Mulleys old car) - Parts car.

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Re: Fitting Air Conditioning.

Post by Way2go »

? If you look under the Technical Archive in BXP, there are downloadable pdf's of aircon and electrical diagrams. :wink:
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Re: Fitting Air Conditioning.

Post by Vanny »

David wrote:Thanks again for the replies. I have looked on the bx project site, and found a topic in fitting ac, but the pictures have gone, including the diagrams. Would it be possible for anyone to post them in here, or send me the diagram directly? Also, I am struggling to see where the pipes go around the air filter unit, could anyone possibly send me a picture of where the pipes and drier fit?
Thanks again in advance.
Tell me which topic and i'll fix the links. The pictures will still be there, just a bit misplaced
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Re: Fitting Air Conditioning.

Post by David »

Hi again, thanks for the replies. The thread was one that came up from the search function, so I don't know which it was.
I have found a wiring diagram, and wired some of it up, but not had time to do much more.
I have also come across more potential issues. The black box compressor controller does not seem to work. It shows on the diagram that it has live in and out and a neutral, but it does not do anything when connected. I have tried the wires all ways to no avail. Any suggestions? I am actually thinking of bypassing the box and just using a switch.

The diagram also shows the 2 heater fans connected in parallel, so I have done this, but I am wondering if it's ok as the heater control resistors have a reputation for breaking. Any thoughts?

Also one of the more serious problems; I have removed the gearbox and flywheel and now fitted the sump. I know it needs a different flywheel, but I am unsure of what exactly it needs. It had a 1.7 na diesel flywheel, with the smaller clutch, but I know really it could be doing with a bigger one for the 4x4 gearbox, so would it be one out of a turbo diesel I need? And would it have the needed groove in the back and also the 2 slots in the sides for the Rev counter?

Thanks again for any advice.
1992 Citroën BX 1.9 Diesel Meteor 4x4 - The Project.

1992 Citroën BX 1.9 TXD (with GTI engine; Mulleys old car) - Parts car.

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Re: Fitting Air Conditioning.

Post by Jaba »

David wrote: I have also come across more potential issues. The black box compressor controller does not seem to work. It shows on the diagram that it has live in and out and a neutral, but it does not do anything when connected. I have tried the wires all ways to no avail. Any suggestions? I am actually thinking of bypassing the box and just using a switch.

The c/u has 7 connections. Reference to the wiring schematic show that the lines to the on/off control and the evaporator thermostat must be in the on or closed position to switch on its relay function to switch on the compressor 12volts.

The diagram also shows the 2 heater fans connected in parallel, so I have done this, but I am wondering if it's ok as the heater control resistors have a reputation for breaking. Any thoughts?

Seems to work well so don't look for problems

Also one of the more serious problems; I have removed the gearbox and flywheel and now fitted the sump. I know it needs a different flywheel, but I am unsure of what exactly it needs. It had a 1.7 na diesel flywheel, with the smaller clutch, but I know really it could be doing with a bigger one for the 4x4 gearbox, so would it be one out of a turbo diesel I need? And would it have the needed groove in the back and also the 2 slots in the sides for the Rev counter?

Two options: grind the sump back to clear the flywheel or find a flywheel swap solution, which will probably be difficult

Thanks again for any advice.
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