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Heating issues

acme

Well-known member
Joined
22 Oct 2007
Messages
875
Inevitably after ten years of ownership you get to know your car and what is/isn't normal.

After about three weeks of not using it over Christmas the battery was completely flat, to the extent that I couldn't unlock via the fob - which has never happened before.

Charge the battery and all's fine.....except the heating/AC doesn't seem to be as powerful as before, either on the regular fan speeds, or most definitely on the large snowflake/full speed of the AC. The AC is working as I can see the clutch spinning up on the compressor.

For a while I've noticed small black particles on the dash top, whenever I use the car I run the AC and always run it for a little while on max to make sure it's all lubricated etc - so I thought perhaps some of the 'fluff' was just old stuff coming out.

Of the vents below the windscreen there's almost nothing coming out of the right hand one, though there is for the right hand one near the door below the steering wheel.

I can hear the blower motor in the rear working, and on position four I can hear air rushing in under both back corners under the bonnet.

So, any ideas, is it anything to do with the battery going (very) flat, or have the mice been nibbling at something - found bait under the engine area.....

I'm thinking stuck/knackered flap/servo?

Cheers
 
Interesting. Mine was stood for close to 10 months when in at Ninemeister for the paint job - and when that came back I had small black particles blowing on to the dash top.
I figured this was due to the crap accumulated during the work - and it stopped after a short period, so I just forgot about it.
Would be nice to know more.....
 
When my system failed I had fairly large bits of very fine blacks film blow out of the vent as well as the little bits. Here's a pic. It looks like the top laminate from vinyl, but can't be sure.

Clearly the lining somewhere breaks down. I suggest that the parts that blew out of mine would be large enough to block (or severely restrict flow through ) pipes if they got stuck across a pipe.

Never heard anyone explain exactly where this stuff comes from and how to remove it rather than just await it disintegrating and blowing through.
 

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This is most probably the thin covering on the foam on the Defrost vent flap. This flap is placed centrally in the air box, at the outlet for the two centre vents.
See the pic below, slightly wrinkled foam covering.

Cheers,
Tore
 

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So, if the foam is supposed to have a thin covering to prevent air passing through it... and that thin covering gone... what happens? Surely the air con won't work as well (or they wouldn't put the stuff there!)

Can this be easily replaced, at next service, perhaps?
 
The air box must be taken out of the car to replace this, and I would estimate this to be a 5-10 hour job. I guess the foam has several purposes, possibly to dampen air flow noise and to ensure proper closing of the flap.
I would think that removing the covering will have little impact on air flow/noise, especially taking into account the work needed to replace this.
However, if you ever are to replace your evaporator, and the air box is out anyway, I would think of replacing the foam.
Cheers,
Tore
 
Many thanks for the replies Gents, appreciated :thumb:

Thanks too Tore, I shall check these out.

I'm assuming when turning max/min heat/fan speed and there's little change on the right handside it means servo issue.....I shall investigate further.

I guess the question is, if it is these how can you change :?:
 
Test all servos first, and we'll take it from there.
HVAC servo change is relatively easy, depending on which one you need to fix.
Cheers,
Tore
 
Thanks Tore, appreciated :thumb:

Gavin
 
ToreB
Can you help us?
When you run the test of the ECU outputs using your OBD lead and scantool.
What is each test doing?
ie, if it's activating 2, what is it actually testing?
I'm sure I had a list of these tests at one time, but I can't find it anywhere.
Do you have a list?
Thanks.
 
I made this list years ago:

Seq. (start): Servo 4; OPEN, Left mixing flap (controls hot & cold air mixing) (993: in the footwell)
Seq. 1: Servo 4; CLOSE
Seq. 2: Servo 2; OPEN, Right mixing flap (controls hot & cold air mixing) (993: in the footwell)
Seq. 3: Servo 2; CLOSE
Seq. 4: Servo 1; OPEN, Defroster flap (center nozzle) right servo in luggage comp. with white horizontal rotating axle
Seq. 5: Servo 1; CLOSE
Seq. 6: Servo 5; OPEN, Footwell flap (leftmost servo in luggage comp.)
Seq. 7: Servo 5; CLOSE
Seq. 8: Servo 3; OPEN, Fresh air flap (middle servo in luggage comp.)
Seq. 9: Servo 3; CLOSE, '
Seq. 10: A/C radiator fan; Low speed, (left front fender behind head light)
Seq. 11: A/C radiator fan; High speed
Seq. 12: Oil radiator fan; Low speed, (right front fender behind head light)
Seq. 13: Oil radiator fan; High speed
Seq. 14: Primary blower fan; Low, (engine bay, above left side of engine)
Seq. 15: Primary blower fan; High
Seq. 16: Secondary blower fan; (dashboard; Left side)
Seq. 17: Secondary blower fan; (dashboard; Right side)
Seq. 18: A/C radiator fan; Low speed
Seq. 19: no reaction (resirc flap valve?)
Seq. 20: no reaction


The servo tests are meant for adjusting the mechanical arms, and does not test if the servo works or has the typical damage. Test movement use brute force and not position feedback as in normal CCU operation.
Cheers,
Tore
 
Thanks for that Tore. That list is perfect.
 
Many thanks Tore for your help, much appreciated :thumb:

Initially the below codes came up. These were cleared and then we went through the Climate Control tests, all appearing to be fine, this we did a couple of times, seemingly without fault.

43 - Rear blower motor speed 1
44 - Rear blower motor speed 2
45 - Inside sensor blower motor

Getting back in the car and firing her up all seems to be well; AC max is now as it was, and the regular 4 speed fan positions are also as they were. Likewise the right hand dash vent now has air coming through it.

I can only conclude the battery going as flat as it did caused the error codes?

Lesson learnt, the solar trickle charger which seems fine in the summer is useless in winter :frustrated:
 

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