C5 mk1 climate control

[Duracell]

Hi - When my wife's 2003 C5 2.0 Hdi is started, the climate control panel initially shows the heater fan running but the fan fails to run, after approx 30 seconds the display changes to show the fan shut - this happens in manual or auto and will stay off until the ignition is switched off and back on again. I'm struggling to diagnose the problem - the hayne's book only shows a wiring diagram for manual air conditioning models - I can't find any blown fuses and I've tried another control panel and fan speed controller without resolving the problem. Any suggestions welcomed.

Thanks

Richard

[waynedance]

You will find it is more than likely the fan motor resistor which is located under the dash to the left of the clutch pedal. Is this what you have already tried?

My fans went funny last year and was not doing as the display suggested. Some say you can solder new parts to the board but I just got a new one.

[Duracell]

Thanks, but I've already tried that, and I've just discovered that the flap motors are also not activating and the ECO button does not work, so I think I've got something more fundamental wrong. I'm trying to relate the 'typical heater wiring diagram' in the Haynes manual to the car, but it does not seem to bear much relationship to it so I'm a bit in the dark at the moment

Richard

[redeye49]

I have a 2002 2.2 hdi semi auto citroen C5 and my climate control started playing up over the last few weeks it was working brilliantly then it stopped working and then it started working and the other day i switched it off and when turned it on again it was just blowing fairly warm air from outside into the car and i left it running for about half an hour and suddenly it started working again and then when i stopped and locked the car up for the night and then the next day got back in and started the car and put the cars climate back on guess what?? yep you got it no cold air and its not worked since then, when in the auto mode will only allow the fan to go to the first speed setting and wont engage the a/c compressor even though the green light is iluminated and when in manual and set to 16 the lowest setting the compressor still wont cut in but it will speed up if i manually increase the fan speed but if i turn up the speed of the fan manually the fan gets faster but still no compressor just air at the outside air temperature!!. if i turn up the air temperature the fan works normally heating up the interior of the car as it should. all of the vents pass air through them as they should so the flaps are all working.
I have had the gas level checked by an automotive mobile a/c firm with a very good reputation and the system has plenty of presure in it and he tells me its an electrical fault.
does anyone have any idea whats wrong ?.
I would be very interested to hear from anyone who has had this problem and if they found out what the cause and cure is.
thanks in advance for any and all help

[KevMayer]

Both these problems seem to me to point to an ECU problem. First try disconecting the battery for a few minutes. When you reconect the battery don't do anything (not even open a door) for at least 30 seconds and everything should reset ok. See if this helps.

If this doesn't help then maybe there's a problem with the temperature sensor input to the ECU. Maybe they're dirty/covered in dust? With dual zone climate control there's probably two sensors.

[legin]

Hi first time on here and I have a similar problem. Just driving along with the air con off when the fan icon went blank but it was still running on about speed 3. I can't put it into eco,temparture seams to work normal,air distrubution normal,rear dimist works and front demist sends air to the screen but doesn't speed up the fan. Will try disconecting the battery as surgested but any other ideas welcome.The system did work normally yesterday on start up for about 1 minute but failed again. My car is a 52 plate C5 2.2hdi SX auto estate 69000 miles.

[waynedance]

Look at post 2

[Lapik]

Hi.
Has anyone got access to original wiring diagram for automatic climate control. Fan has stopped working. I have swapped 3 known good resistors, 4 new resistors from different suppliers and 2 known good control modules - still nothing. Motor runs, if tested with 12V drill battery, but not when connected to the system itself. All displays show no speeds for the blower at startup, rest of the systems are working (flaps moving rear defroster switched on (although it actually doesn't demist as the rear glass is knackered). I'd love to get the old lady back on the road, but it is impossible without working windshield defroster as it is solid MOT fail here in Estonia

[GiveMeABreak]

The blower control modules are designed to slowly spin up the fan motor. When moisture gets into the motor bearings from non use of the A/C system and is allowed to sit there, it can cause the bearings to slightly seize. This can be why the motor will operate when full power is applied to it, but not with the gradual power-up provided by the blower control module.

So possible causes are a) cheap blower control modules or b) possible the blower motor itself.

[Lapik]

Thanks Marc.

Then it will have to wait for spring (it looking a lot like horrible skiing weather) to take the dash out and repair/replace the blower motor and the flaps in one go.

[GiveMeABreak]

You don't need to remove the actual dash, nor any flaps. However, on a Left Hand Drive, to gain access, the trim under the driver's side dash needs removing along with the steering column bolt and shaft (so essential to lock the steering wheel in the dead ahead position to maintain the correct position of the rotary switch in the steering wheel.

[dulenator]

I don't know if there is any difference between MK1 and MK2, but I got the blower out without touching the steering column. I just removed the plastic trim and wiggled the motor out.

[Lapik]

Found some diagrams from different sources and traced the Fuse/relay module in the engine bay to do it's tricks again - seems like it is having its cold solders again in different places. I have resoldered most relays by now, seems like it's time for fuseholders now. Turned out to be voltage drop down to 6. something volts at startup on the feed wire on the resistor thingy. Will take the module out for soldering in few days and then it's time to fit the nice set of leather seats I got for the old gal.