CX Climate Control Aircon heater/AC flap - manual control?

UFO · Unread post by **UFO** » 11 Jan 2007, 03:56

Hoping a few people on here remember what a CX even looks like...

Our recently acquired '85 CX25ie is series 1 of course, but being late S1 it received the climate control aircon system that apparently was installed into Prestiges and Series 2 cars.

The problem appears to be that the AC is working fine (rear AC gets very cold and the front TX valve and pipes get very cold) but I believe the flap in the airbox somewhere is either stuck or its electronic control has fritzed.

What I want to do, to enable Mrs UFO to remain cool, is to manually move the flap so that the only air flowing into the car through the vent system goes over the AC evap and not over the heater core. I have put a tap in place to ensure the heater core is not getting hot coolant feed in the meantime.

Can someone give me an idea if/where I might find the flap so that I might be able to move it? Is best access from the left or right side inside the car OR is it something I can do from the engine bay.

I am sure someone may have an idea. Please....

DoubleChevron · Unread post by **DoubleChevron** » 11 Jan 2007, 05:28

You posted on andyspares about Series I CX's

I think there might be one (litterly) left there

You didn't think we'd find this message and say "told ya so

".

Seriously UFO, the early cars I've seen have a small white motor that runs a geared flap out under the bonnet as the base of the pickup tower (next to the coolant reseviour).

This little motor will turn as soon as you unbolt it ... It's designed to... What should happen is when you turn the air-con full on, the flap will close to recirculation leaving the motor permanently stalled in that direction, turning the air-con off should turn the recirculation off stalling the little motor in the other direction.

You basically just cutting off the inlet pickup at the bottom, if you think the flap is leaking try shoving the inlet tower full of rags so it's blocked and can only pickup air from inside the car.

Good luck... Your gonna need it, 'cos nothing prevents the heat soak in these cars (I should know, I've been driving 'em since I was 16years old !!).

seeya,
Shane L.

UFO · Unread post by **UFO** » 11 Jan 2007, 11:55

Yeah I know what you mean. CX? What's a CX. You know that until Deb's article appears in the club mag that I will not talk about the CX on AF.

Anyway, I think you have probably provided the answer I need. I will search on the weekend.

DoubleChevron · Unread post by **DoubleChevron** » 11 Jan 2007, 12:21

Yeah .... But you know me too well... If I can sh!t stir someone.... I will

The old 2400 of mine used to leak tremendous amounts of agonizingly hot air at the joint where the recirculation pickup joins the main funnel down from the bonnet (you'll spot it easily, it's basically a plastic bit that runs off the side of the tunnel and towards the edge of the drivers footwell).

Check carefully all these connections... *any air* that manages to find it's way into the ventilation under the bonnet, will not only cause smells in the car, it'll transfer mind numbing amounts of roasting air into the car (seriously just trying to bleed the CX's cooling system, to gently rev the engine the air being moved by the fans was so hot, I needed to go put a welding glove on to avoid being burnt.... With the car at 86degrees (low fan speed), the air being blown through that engine compartment is at least 86degreesC ... You really don't want it getting into the intake for the ventilation.

good luck
Shane L.

UFO · Unread post by **UFO** » 28 Jan 2007, 09:41

STOP LOOKING - I fixed it

Today I removed the front passenger seat (LHS), the centre console side panels, the radio/ashtray housing and most of the glovebox assembly - just left the outer one in place as dropping the inner bolt from the engine bay gave enough access.

For a couple of weeks I could hear the motor moving to control the flap when the temp lever was moved from 15 to 30 and back. It seemed to run either continuously or for a long period. At least this confirmed that the motor was doing stuff at the right time. However the heat or cool flap was not moving.

I removed the motor from the left side of the air box and ran it in conjunction with moving the lever. The square mouthed cog (?!) on the end moved slowly but powerfully through about 100 degrees. If I held the motor and tried to stop the cog it was too strong.

I then manually moved the square rod which obviously connects to the control flap. This moved but stiffly. A good spray of INOX soon had that moving better.

After carefully removing the gearbox/control unit from the motor and checking it for stripped gears, I then worked out which direction the motor should be in relation to the flap and indicator. I held the motor firm up to the rod and tested for movement. VOILA! You could hear the flap reaching the end of its travel and stopping up against a seal.

I then screwed the motor back in place and it all worked. I then proceed to reassemble the dash - but that is another story!

End of the story is that the CX now has proper control in the front for heat and cool air flow and the aircon seems to be pumping out some cool air. It will get a test tomorrow on a run to Sydney.

Unread post by **alan s** » 28 Jan 2007, 12:16

UFO wrote:STOP LOOKING - I fixed it

End of the story is that the CX now has proper control in the front for heat and cool air flow and the aircon seems to be pumping out some cool air. It will get a test tomorrow on a run to Sydney.

If it's anything above 20 degrees, make sure the window winders work before you leave.

Also, if you drive there and back with the air/con going, please tellus an honest tankful to tankful fuel consumption figure so these guys can have a good laugh/shock horror.

Alan S

$\:D/$

UFO · Unread post by **UFO** » 29 Jan 2007, 03:12

Electric winders work well, now that I have cleaned them. The left was dicey for the first couple of weeks.

Fortunately the rear a/c head pumps very well and it deflects off the blinds and falls over the top of the front seats. It could be interesting when I get the beastie on the freeway to see if accumulated leaves and dust blow off front the a/c coil as it may not have had airflow over it for a couple of years but certainly would have collected dust from the country roads it has driven on. There is so much fine dust in this car I could nearly top dress the front lawn!

DoubleChevron · Unread post by **DoubleChevron** » 29 Jan 2007, 03:58

I think fuel economy will only be affected marginally.

You see you have a later injected, tracter motor with AEI ignition as well, the bigger 2.5litre motor and a modern rotary compressor (not the hidious old single piston compressor). I've gone blank and can't recall what the big old single/twin compressors are called ??

If there's a measurable difference in fuel economy over the 18mpg you'll probably get anyway, I'll be surprised

That's all the Chris stewart gets out of his, given the huge number of round-abouts and intersections in his daily drive, not to mention the cold starts.

seeya,
Shane L.

Mandrake · Unread post by **Mandrake** » 29 Jan 2007, 04:31

I've often wondered if air-con is as power wasting people make out...

Sure, it might use a few HP, but how many HP does having all the windows down trying to keep cool waste, at open road speeds ?

I havn't seen any figures for it but I'd be willing to bet that the extra drag from having several windows down at 100Km/hr would be more than the power used by a modern air-con compressor....

Different story in start stop traffic of course, but if you're hot you don't have much choice...

(Boy am I glad my air-con is working 100% this summer!)

Regards,
Simon

UFO · Unread post by **UFO** » 30 Jan 2007, 05:22

Let's not start the hoary old windows down V aircon argument again. It has been proven multiple times that aircon on is more efficient than windows open.

Anyway, the car seemed to use between 1/3 to 1/2 a tank for the return journey of around 180km. About 1/2 of that is through city traffic especially on the way up it was fairly stop start.

The air in the front was cool but not cold. I think as Shane has suggested before more insulation around the intake tower would help.

On the way home we drove away from the meeting hall fine (Mrs UFO drove her car home) and about 2km away as she stopped at a set of lights the car coughed and reduced to what seemed to be three cylinders. She kept it running and crawled to the other side of the intersection when the lights went green and stopped under a street light. This is 10.20pm and we have 80km to drive home mind you.

I started checking plug leads etc but it was a bit hard in the dark and I had forgotten to bring a torch. Next thing I know two club members pull up in front in a new C5 HDi. One of them is a CX expert and immediately started to tell me how horrible the coil packs are. We got some light from his reverse lights and then I touched what turned out to be the power feed to one of the coils and it fell away in my hand. AHA! I pushed the plug back on and sort of secured it, signalled to Deb to start the car and VROOM! It was fine. Car cruised home beautifully.

Mind you all this was after I had shown photos and told the meeting about how we had recently rebuilt the XM engine. I thought the Citroen eye had it in for me, but was obviously only reminding me of its presence!

DoubleChevron · Unread post by **DoubleChevron** » 30 Jan 2007, 06:01

Yep,

coil plugs .... and don't forget to carry a spare flywheel sensor with you.

She'd have been really limping along, without a coil you drop 2 cylinders. Each coil fires 2cylinders.

I suggest cleaning up the wiring around big blue and the radiator fans relays/plugs before it bites you.

seeya,
Shane L.

Unread post by **alan s** » 30 Jan 2007, 07:16

UFO wrote:Let's not start the hoary old windows down V aircon argument again. It has been proven multiple times that aircon on is more efficient than windows open.

Only in theory it has. On a CX it will absolutely destroy the fuel consumption.
Best I ever got out of a CX with air was my old silver car after the previous owner had spent mega bucks having work done on it and that got around 15mpg. The 2200 with air got down as low as 9. It was so bad that I couldn't drive as far as Gympie on a tankful and as in those days there were no servos in between, it meant I had no option but to drive without it. From here, that's a 2 hour drive and the tank was what 65 litres?
If you can get rid of that heat load it might go better, but the last CX I owned as you know would travel around 8.6 - 9L/100 klms which is over 30MPG, so where's the argument if an air/con CX can't do at least 8 - 8.5 L/100 klms?

Alan S

PS. IIRC coil packs from a V6 Commode will fit straight onto CXs that use them and for about 1/4 of the price.
Wreckers apparently will nearly throw them at you.
Pretty certain Brad needed to swap the ones on our GTi and that was what he used.