Unusual aircon fan behaviour

[Capesthorne]

Afternoon all,

My girlfriend has recently taken ownership of a 2005 C220cdi Sports Coupe (purchased from a friend), whcih she is very happy with.

As of last night, it has started behaving very strangely as follows.....

When you press your foot on the accelerator, the aircon blower rises and falls in line with the revs of the engine. Also, the only vent the air is coming out of is the passenger vent closest to the window. I have taken it off auto and back with no change, changing the speed of the fan also has no impact.

The system blows out cold air, so that is working well, but there is something very odd going on elsewhere.

The display in-between the speedo and rev counter is showing that I have one malfunction, but I have no idea what that is, is it something that can be read without specialist kit?

Many thanks for your advice in advance chaps

Regards,

Bryn
http://www.mbclub.co.uk/forums/

 

[Capesthorne]

Quick update guys.

I have noticed that when the blower is set to it's lowest speed (off in fact), the fan will still rise and fall with the revs accordingly. All very strange, I am guessing by the lack of responses that I am not the only one who is perplexed.

As before, any feedback appreciated.

Cheers,

Bryn.

 

[richard]

If you use the steering wheel buttons you can scroll through and see what error is being reported - the errors reported there are normally things like bulb failures, or major safety failures (reported in red)

Richard

 

[Capesthorne]

Thanks Richard, I had another play and found the error function, it was the screenwash! My g/f seems to be under the impression that screenwash is my job because it is car related, so some gentle realignment of responsibilities is required I think

No change on the fan though, still odd.

 

[richard]

It will be your fault when the crash occurs because g/f couldn't see out the windscreen too.

The fault could be a broken aircon control unit, but I'd also have the alternator and battery checked in case the voltage of the car is raising and lowering (instead of being pretty constant) which may cause other things to break.

Richard

 

[Capesthorne]

Hi all,

Apologies for the delay in responding, work and usual niffnaff got in the way.

So, an update on the 'blower' issue. The mystery was solved as soon as I was on the road to driving the car to the garage, where I managed to drive the car with the window open and at a decent speed.

As I was driving along and depressed my right foot (window open) a loud whoosh could be heard from outside, to which I immediately thought that must be the turbo pipe, which indeed it was. Pipe was duly replaced by Alan Lloyd in Kingston for £120 and all was back in order.

Nice simple fix!