Help regarding C5 A/C

[atr]

Hi
I have an ongoing problem with overheating in my C5 2007 petrol vehicle, which causes odd things. one of them is that my A/C stopped working.
I've entered the control panel and entered the A/C icon by pressing the "OK" button and the upper line says "Cut air conditioning (A/C off)".
All my attempts to change this setting (I guess to A/C on) were in vain. is there any way to change it and to turn the A/C on?
Thanks for your help.

[xantia_v6]

I think that you may need to connect your Lexia and do a more detailed diagnosis of the state to the A/C system. I suspect that the message you have on your display is a warning, not a setting.

[Stickyfinger]

If the car is overheating, the AirCon will not switch on I think. On my X7 it was when the engine cooling fan was faulty.

WHY would you worry about the AirCon if the Car is overheating ?......fix that or you will soon not have an engine to power the aircon anyway.

[atr]

It is quite a story. the car was overheating, so I went to a shop that specializes (or so he claims) with radiators. he replaced the radiator and the vehicle was still overheating, so he replaced the water pump. I rode home (about 25km's) and I've noticed that water is leaking. (that was on thursday). because I didn't want to risk the engine, I haven't used the vehicle until this morning. I drove early in the morning back to the shop, the A/C worked fine. I've reached the shop, the owner checked where the leak is from and he found out that they didn't connected well the rubber hose to the expansion tank. he fixed it (or so I hope) and then I've noticed that it's still overheating and the A/C does not work. he called the electrician who in turn checked the vehicle and came up with the conclusion that the fan is faulty. that's when I've stopped the whole saga by telling them that that's enough. I took the vehicle and drove back home, ca. 25km's as I've mentioned earlier. to my surprise, it didn't overheat a bit , which brings me to the conclusion that there is nothing wrong with the fan, but somehow the A/C stopped working from that event. why? I dont know.
Thanks for your patience to read the story so far (as it is not completed yet).

[Paul-R]

If the fan isn't working then the A/C will not operate. At startup the A/C ECU checks the state of the fan and if it doesn't work then then neither will it.

Re: overheating. Obviously when the car is stationary, and if the fan doesn't work, then the coolant will get hot. As soon as you start moving through the air then this will start to cool the radiator down.

Also, did the mechanic bleed the cooling system after changing the water pump? The engine can overheat if there are air pockets stopping the proper circulation of coolant. He would also need to check again after tightening up the hose as this might have let air in later on.

[atr]

Hi Paul-R
As per your question regarding bleeding the air from the cooling system - yes he did. not exactly according to Citroen's procedure but he opened the three valves on the pipes and the air bleeding plug on the radiator.
Now, about the A/C working only when the fan is on - when the engine is started and the coolant is sill cold, the fan wouldn't work, but as far as I know and please correct me if I'm wrong, as soon as the A/C is turned on - the fan will start working, even if the coolant is not warm enough to operate the fan.

[Paul-R]

That's as I understand it as well. But, correct me if I'm wrong, your electrician has told you that the fan is faulty therefore that doesn't happen.

Is he sure the fan is faulty? Has he tested it by connecting it directly to the battery? Or could it not be operating for a different reason, say a blown fuse?

[atr]

That's as I understand it as well. But, correct me if I'm wrong, your electrician has told you that the fan is faulty therefore that doesn't happen.

Is he sure the fan is faulty? Has he tested it by connecting it directly to the battery? Or could it not be operating for a different reason, say a blown fuse?

No, he didn't connected it directly. I've asked him if he can connect it/bypass the fan relay so that it will work constantly so that I will be able to drive home without doubt if the fan is working or not, he looked at me as if I was a complete idiot telling me that it's not possible since it might cause damage to the computer (meaning the ecu).
Anyhow, the saga goes on. I've decided to take the vehicle to another mechanic that I know that specializes in Citroen vehicles. I drove to him early this morning (he is located about 50km's away). before I've started the engine I've checked the coolant level. I had to add about half a liter.
when arriving, I've checked under the vehicle and there was no sign of leak. (the engine was turned off). to my surprise, about 10 minutes later, I've noticed that there is a leak, but it seems that the leak is from the water pump area. after telling the mechanic the whole story, he said that the leak might be a result of replacing only the water pump itself without the back part of it and since the original pump is made of plastic, along with its base, and the pump was replaced with a new pump that's made of metal, somehow combining the metal pump with the plastic base might cause the leak but he will check it thoroughly. what I missed to mention yesterday is that the first mechanic told me that he is replacing the pump because it might be that the pump's impeller might become loose on its shaft, because of the heat. he also removed the thermostat in order to see if it causes the overheating.
so, as I wrote, I took this morning the vehicle to another shop and I'm waiting for the results of his examination.
I'm writing all this events in such a detailed manner in a hope that if some of you members of the forum will (god forbid) find himself facing such a problem, he will be able to learn a bit from this experience.
btw - when I was driving this morning, the A/C wasn't working but I guess that the fan did' since the temperature seemed normal on the gauge.

[Paul-R]

Well please let us know what happens, You're in the unfortunate position of having several different people making changes to the car. That leaves lots of room for finger pointing and transferring blame!

...what I missed to mention yesterday is that the first mechanic told me that he is replacing the pump because it might be that the pump's impeller might become loose on its shaft, ...

I have heard of this happening but not for a long time.

btw - when I was driving this morning, the A/C wasn't working but I guess that the fan did' since the temperature seemed normal on the gauge.

Not necessarily if the forward movement of the car pushed enough air through the radiator.

[atr]

Well please let us know what happens, You're in the unfortunate position of having several different people making changes to the car. That leaves lots of room for finger pointing and transferring blame!

With all respect, I don't see it as a matter of "transferring blame" since I didn't even went back to the first mechanic. I've came to the conclusion that if the fault was not fixed the first time and was not fixed when I've returned the second time, then I reckon that he is not able to fix it. anybody can make a mistake once, but if you are not able to fix it the second time, there is no point in stretching it over and over.
As for the problem itself - the second mechanic just called a short time ago and told me that the water pump "combination" is leaking and must be replaced (you know what it means to replace the water pump) and the fan must be replaced as well. the cost of it? it's exactly half of price that I've paid for the whole vehicle.
My only hope is that is the end of this long and frustrating saga.

[white exec]

The fan motor will be an expensive item, and they rarely fail. Has/have yours (there may be one or two of them) actually been tested by running it/them independent of the normal vehicle supply?
The three relays (for twin fan) and relay/resistor (for single fan) can suffer from dirty contacts; easily sorted.
If the water pump is leaking, that obviously needs sorting or replacement.
It is essential that the Citroen recommended coolant system filling/bleeding procedure is followed; it often involves using a bottle as an additional "header" tank. Individual bleeding screws/valves can be overlooked too.

[dnsey]

The fan and its control system can be tested via Lexia, which is the only real way to be sure that it's functioning correctly. It would be much cheaper to buy a Lexia interface than to replace the fan unnecessarily, and you could then also see why the aircon is being inhibited.
It's worth checking first that the fan isn't seized, which isn't unusual, and can often be cured easily with a bit of manual excercise.

[Paul-R]

It's worth checking first that the fan isn't seized, which isn't unusual...

It certainly isn't. It happened to both my Xsara and 2003 C5.

...and can often be cured easily with a bit of manual excercise.

Failed to free off either of the one that seized for me sufficiently. One wouldn't move at all and the other one freed off a bit but not enough to spin freely.

[atr]

Hi
Thanks for your comments. as I mentioned earlier - the (second) mechanic checked the fan and told me that the fan is faulty. he noticed that when the fan isn't working when it's supposed to and he hits on it lightly, it begins to work (might be that the brushes are worn or some other reason) anyway, he is convinced that the problem is there. I hope that that will be the end of it. the vehicle should be ready today, so we'll see.

[white exec]

A fan could be reluctant to spin up if it was being suppled with insufficient current (eg via a corroded contact or relay), and clouting it may well get it moving. It is essential to check the fan with an independent supply, before condemning it.
Just trying to save you money!!