CABIN HEATER NOT WORKING!

Birchall said:
The sensor for the temperature that will affect this has TWO circuits and even if the temperature gauge was showing perfectly correctly it still might be the cause. One circuit operates the gauge and the other circuit (in the same sensor (4 wires) feeds the temperature to the ECU to enable it to make decisions on what to do about fuel mixture and also the climate fan etc.
These sender are known to fail.
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That puts my mind at rest a bit that at least if the gauge is not working that the ECU could still be getting the correct data. However, if the climate fan is also playing up that could mean that the ECU is not getting the correct data, which would be bad.

Birchall said:
My advice is (as I have said) that basically your temperature gauge should be reading 90 when the car is fully warmed. Yours is not.
So the engine is either running colder, which is matching the symptoms you are having, or the sender is broken.

But replacing both at the same time makes sense here no matter what the Fan is doing (in my mind).

Eliminate the less costly and easier to fix options first and since there are many A2s that have a broken sensor and/ or a failed thermostat it will not be a bad thing to "refresh" those anyway. THEN you can have a car that runs at the correct temperature and with the gauge showing that and so then you can look at other causes if you still have the problem.

Eliminating possible and/or likely causes is not a bad approach.

Steve B
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So, the advice is replacing both the sender and the thermostat first, no matter what previous garages have said about the wiring and the thermostat?
That sounds like good advice - your post certainly makes sense to me.

Is it unlikely that there is a wiring issue between the sensor and the gauge then?
I guess the only way to find out is to replace both the sender and the thermostat to make sure that the ECU is getting the correct data and the engine is not running cool.
 
Au2ro said:
Is it unlikely that there is a wiring issue between the sensor and the gauge then?
I guess the only way to find out is to replace both the sender and the thermostat to make sure that the ECU is getting the correct data and the engine is not running cool.
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The only thing I have ever found that was wiring related was on a car where the inside of the sensor connector was soaking wet. That was causing the main problem, but that is rare. The looms can be a bit of an issue, but not normally this part of the loom. No harm in taking the plug off and squirting a bit of WD40 in there if it is damp and having a llok at the condition of the connector and wiring, just in case?

Steve B
 
Birchall said:
The only thing I have ever found that was wiring related was on a car where the inside of the sensor connector was soaking wet. That was causing the main problem, but that is rare. The looms can be a bit of an issue, but not normally this part of the loom. No harm in taking the plug off and squirting a bit of WD40 in there if it is damp and having a llok at the condition of the connector and wiring, just in case?

Steve B
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Well, that sounds like something that I can do myself OK before taking it to the garage.
 
MY OB11 doesn't show a fault however, my independent garage with a Bosch diagnostic get a fault code for flaps. They are seeking advice before they revert to me. I have had a quiet moment to listen to the flaps and you can hear them moving (or trying to move). Despite coming up to temp the fan has not worked. Suspect garage will revert with a couple of options. Any suggestions here welcomed.
 
jtmalmesbury said:
MY OB11 doesn't show a fault however, my independent garage with a Bosch diagnostic get a fault code for flaps. They are seeking advice before they revert to me. I have had a quiet moment to listen to the flaps and you can hear them moving (or trying to move). Despite coming up to temp the fan has not worked. Suspect garage will revert with a couple of options. Any suggestions here welcomed.
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One thing to be careful of is in the 50 or so A2s that I have run a free scan for using the genuine VCDS kit I would say that 90% of those cars threw up multiple faults relating to the HVAC (Air con / climate) controller., even though there were no problems in the way the system operated.
Add to that, when scanned, it will show all of the intermittent error codes that have occurred since the last scan. So if one flap had a minor "wobble" one day, that will show as an error.

So all I am saying is that if anyone has a list of Climate errors and yet the system seems to be functioning doesn't mean that you have to spoend money correcting them.

If, as in your case, you have a non operating fan, then it may well be just the fan, regardless of all of the other codes. Replacing flaps is costly, so please check the cheaper and easier to check bits first.

Steve B
 
Birchall your absolutely right! I've had the same problem in the cabin heater problems had it scanned at the garage it came with the code HVAC also but it turned out to be a seized fan motor. Got it all lubricated and it's up and running for the time being but I also wanted to know does vw polo 9n fan motor is the same as the a2? Is it a direct replacement?. Thank you
 
Are there any pictures or instructions for removal of fan / flaps so that I can eliminate either problem. Access to fan and see if their is power / drop 12 v on it see if fan works would be a good start??
 
jtmalmesbury said:
I have had a quiet moment to listen to the flaps and you can hear them moving (or trying to move). ... Any suggestions here welcomed.
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I have been driving the car with no heating fan running and no temperature gauge working over the past few days and have discovered that the side vents get warm after a period of time, especially if I crack he windows open a bit.
Also, if I set the flaps to the up position with the controls on the dash the centre vents will get warm too.
So, at least for me I do thik that these flaps are working.
I have had to use a squeegee on the inside of the windscreen to 'demist' it before I can drive as it does not demist by the windscreen vent for quite a while after starting to drive it.
I am taking it to the garage tomorrow to ask for the sensor and thermostat to be replaced and work from there.
 
Apparently I need a "climactic control unit" it's a passive fined unit near the fan that the climate control sends its signals to, to run the fan etc. (or something like that).
The part is not available from Audi (back order only).
Does anyone know where I could get one?
 
Au2ro said:
Apparently I need a "climactic control unit" it's a passive fined unit near the fan that the climate control sends its signals to, to run the fan etc. (or something like that).
The part is not available from Audi (back order only).
Does anyone know where I could get one?
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Hi,

You seem to now be going down another avenue. On Monday you said you were taking the car on Tuesday to have the thermostat and sender unit changed. Has this been done? Your first post described symptoms crying out for this change, and were given good advice here to do so, and without the engine side sorted the cabin side will not work properly. ( I find it very odd your garage advise the symptoms are nothing to do with the thermostat).

Andy
 
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Not going down another avenue Andy, I have had the sensor and thermostat replaced, but the fan was still not turning, the fan motor is broke (readily available replacement) and the "fan speed controller" (for want of a better description) AKA "climactic control unit" (possibly not the correct technical term) also needs replacing, this part apparently is not readily available hence the request.
A wiring fault was also fixed (ABE).
Sorry for the brevity of my last post.
 
Au2ro said:
Not going down another avenue Andy, I have had the sensor and thermostat replaced, but the fan was still not turning, the fan motor is broke (readily available replacement) and the "fan speed controller" (for want of a better description) AKA "climactic control unit" (possibly not the correct technical term) also needs replacing, this part apparently is not readily available hence the request.
A wiring fault was also fixed (ABE).
Sorry for the brevity of my last post.
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There are lots of the fan speed controllers on eBay for around £9 I am sure that is what is meant, I am not aware of any other component involved

. For example.
https://www.ebay.co.uk/itm/Heater-Blower-Fan-Resistor-For-Audi-A1-A2-Seat-Ibiza-Skoda-Fabia-VW-Fox-Polo/122845355151?fits=Car+Make:Audi|Model:A2&epid=1289028176&hash=item1c9a275c8f:g:yY4AAOSwGzhaJhTw

Steve B
 
There is one on the radiator fan, but I have never seen the one on the cabin fan?

But that is obviously the one (looking at the ebay advert and part number) and it is just that I haven't seen one or had a problem with one before.

Why not buy one of the eBay ones?

Steve B
 
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Well, I have not seen it personally, but had it described and a picture shown to me the picture looks like the ebay ones, but could it be likely that it is a fan controller that controls the radiator fan and also the cabin fan on an A2 with climate control?
 
I am sure that someone will come along shortly and confirm that this controller is for the radiator fan AND the cabin fan.

I would like to know what test they did on the controller to deem it as the cause though. Nit questioning their expertise, just surprised at the diagnosis.

Can anyone confirm how easy it is to bypass the controller to test the fan motor itself?

This is a part of the electrickery I have not played with!

Steve B
 
As far as I am aware the fan motor was bench tested with appropriate voltages and the fan controller was checked with a multi-meter.
 
OK, then I guess you could ask A2Steve for one (There is a good chance he would have one.) and cheaper than eBay too.

Steve B
 
Au2ro said:
?.......

But need to know the part number that is suitable for my A2 with climate control before I buy.

Any advice on a part number for a fan motor would also be appreciated as I also see several of them on eBay but don't know which one to get.
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Pleased to see you are making progress with your problem.

I will try and help with the part number but I lack expertise to pin point exactly. Some points....

The eBay item you mention quotes all years so my guess is it universal across the range and age and their warning is their standard disclaimer. A Google search of their part number yields a reference in the "official" VW parts database below. There only seems to be one version, although there is second reference to hot climate but I don't think that applies to us! What puzzles me is the lack of reference (just a hypen) to the diagram, which I take to mean it appears on another page. God knows where, I struggle to find my way around this parts database, our bible. Help anyone? If you have not used the database be advised it is unofficial and full of seedy links, just ignore them.

Lastly in an earlier post you say part not available from Audi (on back order). I assume you mean not available quickly, back order normally means about two two weeks as it has to come from Germany. Audi will cost an arm and a leg, no, only a small part so only a hand! As Steve says ask A2Steve and if it is universal he can take it off his current breakers and you will have it in a couple of days for a few pounds.

Sorry I have not been much help.

http://www.oemepc.com/audi/part_sin...hg_ug/959/subcategory/959050/part_id/0/lang/e

Andy
 
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