Brian50

Well before trying the dianostic route I checked all the connections and fuses again. This time I found a 5amp fuse on L21 circuit under the bonnet kept blowing. Further investigation on internet found this fuse is for the fan control unit and for the electric cooling pump for the turbo. To cut a long story short when I disconneced the electric pump the fuse would not blow and my cooling fan would cut in and my air conditioning worked, the the problem was with the electric cooling pump. This pump is designed to run for several minutes after the engine stops to pump coolant through the very hot turbo prolonging turbo bearing life. When this pump fails it shorts out causing L21 5amp fuse to blow which in turn stops your cooling fan working and the air conditioning. The c5 1.6 petrol THP uses the same engine as the mini cooper s . BMW did a recall on this electric pump as sometimes it caught fire when it failed this resulted in 89 thousand miniS having this pump replaced with an improved version. Unfortunately Citroen/Peugeot did no recall however on PSA cars its the fuse that blows. So I now know I have a faulty electric pump so I priced a new one from Citroen part number 98 067 907 80 and it costs including vat 198 pounds!!! I then priced the same pump for the mini cooper s part number 11 537 630 368 and it costs including vat 33 pounds and 42 pence. So I ordered the mini version from BMW checked it against the old one before fitting (no difference same manufacturer part numbers etc.) The car is now fixed air con works cooling fan cuts in and I can hear the electric working when the engine stops. And the best bit is it only cost 33 pounds not 180. So if your air con does not work first check if the cooling fan is working then listen if the electric cooling pump operates before getting it regased. Many thanks to everyone who helped me with this fault. Brian50

Tried a new relay/control unit today but fault still there. Will go down the dianostic route now I will keep you posted of outcome.

Thanks for the update. Had a look at the car again today to check if the cooling fan motor was ok. Disconnected the wiring harness and ran two separate wires directly from the battery to the two spade connectors on the cooling motor. The fan started right away proving it was working ok. I read some DS3,C4 and Peugeot forums that stated the relay/control unit located at the top back of the radiator could be at fault as you have stated too. It's location is very easy to allow removal it only took me ten minutes as you don't need to remove the bumper. You can remove it without removing the air intake trunking but it makes it easier to remove the two wiring harness plugs and one torx screw. I am going to order a new one tomorrow and hopefully that fixes the problem. The price from the Citroen dealer is 41 pounds plus vat. The parts man informed me he has five in stock as they sell a lot!! If this doesn't work I will need to get a dianostic check at a cost of 70 pounds!! Thanks again for your great advice and I will let you now how I get on.

Yes the engine did overheat as the temperature gauge was reading very high then a message appeared "switch off engine coolant system fault". I checked the fan and it was not running. I only discovered this as you mentioned (in my other post) that my air conditioning may not be working if the cooling fan does not operate. So I need to find out why the cooling fan is not operating. Before doing a dianostic check I want to check the basics this like fuses, relays electrical connections etc. I have found fuses in the engine bay and glove box and all are ok but I don't know where the relay would be for the cooling fan and any help would be appreciated on this. Thanks again Brian

I have a 2012 C5 1.6 petro THP with 20k on the clock. Can any tell me what are the common faults that would cause the radiator cooling fan not to cut in resulting in the engine to overheat if caught in a traffic jam etc.. The fan moves smoothly if turned by hand. Don't have a manual for car so don't know where any relay.is located or fuse etc. Any help on this issue would be be a great help. Does anyone in the Glasgow area have Lexia that could diagnose this fault, local dealer wants £70 just to pug his computer in !! Thanks in advance. Brian

Hi I checked if the cooling fan was cutting in andfound it wasn't. WHERE I live Idon't sit in traffic jams so I have never had the car overheating as it did today in my driveway. So it looks as if my air conditioning is not working because my cooling fan on thr radiator is not working. My next question I hope you can help me withis are they any commonfaults that would cause this on the C5. The fan turns freely by hand so it is not seized , and the car has only done 20k? Again thanks in advance. Brian

Many thanks for your help/advice on this. I have the blower on and the compressor does no kick inI can this this when looking at it (the clutch does not move). I have priced a pressure switch from Citroen 115 pounds plus vat!!!!. I also priced a compressor 635 pounds plus vat!!!! I will check if the cooling fan is cutting in I did not know that if that was faulty it would cause the air conditioning not to work. Thanks again Brian

Hi I have a petrol 1.6 THP 2012 C5 ( 20k on the clock) with the air conditioning not working. Got a local garage to fully charge it with gas which they did but the compressor is still not working. They said there was no leaks found. Any suggestions what it could be, any common faults etc. Thanks in advance Brian

Thanks I have not touched anything but I have notived since my posting is the drivers side has to be set to 23 degrees to get the same temperature as the passenger side which is set at 21 degrees. After reading Car Mechanics this month who have an excellent aryical on c5 heaters I Think it could be the stepper motor at fault on the drivers side. I will take it back to the dealer for them to fix. Thanks

Yes I have an extended Citroen warranty.

Car has only done 5k is it a big job on the mk3. Thanks

I have a 2012 c5 1.6 THP my first Citroen. Can anyone tell me is it normal for the to blow out cold air through any vent unless I have the temperature set to 23 degrees or higher. Any advice would be grateful.