Rear Aircon System and Heating

[yeshu26]

58 Plate VW Sharan. Engine code: BVK

Car AirCon is in tip top condition, as I can feel the AIRCON-pipes in the bonnet Hot and ice-cold respectively when aircon is turned on.

Problems:

1: Front fans are blowing air, but NO AIR FROM THE ROOF FANS at any fan speed. Nothing.

2: Even when front fans are blowing HOT air, there is ice-cold air an egress point/ventilation in the carboot area.

As a result of 2 above, car fogs up due to imbalance in the air temperature.


Please help.

[johnnyroper]

So the rear heater/air con does nothing at all when controlling from the panel?

Check the motor in rear heater box see if you got power to it

[yeshu26]

Yes you are right. Nothing no effect.

Where is the rear heater located?

[johnnyroper]

Nearside in boot behind the quarter panel trim.

[yeshu26]

Ah, thats what the issue is!

That blower is working, and at all times blowing icecold air. Any instructions on how to open it up?
And what am I testing with a multimeter.

thanks

[johnnyroper]

So the rear blower motor is running all the time but the temp control is not working then?

Take the quarter trim off then you can access the heater box,never had mine apart but I did have quarter trim off the other side and it was just a matter of removing C post trim, d post trim and some screws in the quarter trim then it pulled away if I remember correctly.

[Chrispb]

Also worth scanning the HVAC module with VCDS. May help pinpoint the problem.

[yeshu26]

Waiting for the VCDs from a pal.

Until then, any instructions on how to remove those trims?
Also is there anything I could do with Fuses and a multimeter?

thanjs

[Chrispb]

This is the procedure for the MK2 Galaxy

https://www.fordmpv.com/smf2/ford-galaxy-common-faults-and-problems/galaxy-rear-quarter-door-card-removal-(tailgate-side-panels)/

[yeshu26]

Thank you Chris.

1: What am I looking for there?
2: Why this heater is blowing ice-cold air, but that air never reaches the roof fans/ventilators?
3: How does the air ventilation mechanism works in my air? any links or pictorial?

4: Is VCDs worth buying from fleabay, of there are proper dealers for it?
thanks all

[johnnyroper]

The air to vents is through duckting in the trim that goes up the panel between quarter glass and tailgate opening.

Mine never had rear air con so no idea how it works,does it have a flap that diverts air to ceiling vents when in cooling but when in heat just blows out of the heater box at floor level like the standard heater type?

Where is the ice cold air blowing from then if it does not reach the roof vents?

[yeshu26]

This blows icecold air when rear fans turned on.

[johnnyroper]

thatââ,¬â,,¢s the heater outlet which suggests to me the heater is trying to heat the cabin as controls are requesting but you either have a problem with the coolant supply to matrix or the mix flap is not working.

With engine up to temp have a feel of the hoses underneath and see if they are warm and report back what you find

[Chrispb]

Thank you Chris.

1: What am I looking for there?
2: Why this heater is blowing ice-cold air, but that air never reaches the roof fans/ventilators?
3: How does the air ventilation mechanism works in my air? any links or pictorial?

4: Is VCDs worth buying from fleabay, of there are proper dealers for it?
thanks all

1. You ask how to remove trims!
2/3 Only heated air should come out the floor vent, try selecting maximum cold air on the display to see if the cold air is directed to the upper vents, if it does then either the air blend door is not operating (this will show as a fault in VCDS) or you have a coolant blockage to the rear matrix.
4. Anyone who works on VAG vehicles will tell you how invaluable having this piece of equipment is, they are easily available on ebay, don't be tempted to register the software unless your really confident with it you can still check for fault codes but you won't be able to do an autoscan just make sure you get one that's compatible with your laptop.
There's help in our reference library if you get stuck.

[yeshu26]

Findings:

10 mile run on motorway with engine temperature less than 90 (12 0 clock).

a: Both front and rear climate buttons  on "LO", both generate ice cold air as expected. THE AIR only comes out of the carboot vent, as mentioned above. No air whatsoever from passenger seats vent and no air from the rear(car-boot) roof vents either.

b: Both front and rear climate buttons on "HI", front is red hot as expected.  THE AIR only comes out of the carboot vent which is ICECOLD.
No air whatsoever from passenger seats vent and no air from the rear(car-boot) roof vents either.

3: Sorry Chris, what I really meant to ask, once I open those trims what am I testing with a multimeter?

thanks again

[johnnyroper]

You have a flap issue as it should blow from ceiling vents when on cold, vcds will help you identify if there is a motor problem for the control flaps.

Have you felt the hoses/pipes under the car to see if they are warm?

[yeshu26]

Ok off toe fleabay to order one.

Anyone have a diagram or something which shows how the air flows?
Any pictorial on accessing the flap please? Where exactly it is in the car?.

thanks

[yeshu26]

Can I check any fuses or relays with a multimeter in the meanwhile?

[johnnyroper]

Once you access the box it will be obvious what way air flows.

did you check the water pipe/hose temp in to the box to rule out coolant circulation issue?

Donââ,¬â,,¢t think fuse related personally but have a look in ref library as info on fuses and relays for the car in there.

You have a flap/control issue and poss coolant circulation. But the test of pipes will prove or disprove the circulation

[Chrispb]

Number 7 is the door motor this will direct the air to the roof or floor vents, don't know whether it works on full 12 volts or lower

[attachimg=1]

[yeshu26]

Number 4 hose pipe got my attention. Can I feel them under the car somehow as Johny recommended?

[yeshu26]

PS: and so did number 7 the temperature blend actuator.

[Chrispb]

Yes there are 2 pipes one being the flow the other return. In the picture number 4 is only pointing to one pipe but they are side by side.
Under the car you will see the two aluminium tubes, you should also see the two aircon pipes.

[yeshu26]

"You have a flap issue as it should blow from ceiling vents when on cold, vcds will help you identify if there is a motor problem for the control flaps."

Is this flap located in the same box (car boot area) as you folks mentioned?

[johnnyroper]

Yes all flaps for rear heater/air con unit will be in same unit as thatââ,¬â,,¢s where heater matrix and 2nd evaporator live

[yeshu26]

Thanks gentlemen for taking time on your weekend to reply to my queries. Much appreciated.

Will jump into local hardware shop to buy a "star type" tool first. No idea why Germans make things so complex. Opening  bolts to change the pollen filter is a pain! My Sunday rant over!
ta guys

[yeshu26]

OK. nothing on VCDs scanning. It says no fault code found.

[johnnyroper]

Did you check the coolant pipes in to box?

[yeshu26]

Did you check the coolant pipes in to box?

I felt the two pipes into the AUX heater and two out from it. They all are hot. Were you asking about those?

[johnnyroper]

Those will be leading to the rear heater so safe to assume heater matrix is getting coolant.

As for the problem with no faults on vcds I will assume control side and motor is working as it should. I suspect the flap inside the heater box is broken or dislodged.
You need to get in to the heater box and have a look now I think you have done everything you can without stripping it down

[yeshu26]

Ta Johnny

You mean the heaterbox as described in the diagram posted by CHris P above?


best

Those will be leading to the rear heater so safe to assume heater matrix is getting coolant.

As for the problem with no faults on vcds I will assume control side and motor is working as it should. I suspect the flap inside the heater box is broken or dislodged.
You need to get in to the heater box and have a look now I think you have done everything you can without stripping it down

[yeshu26]

*Update*


Without doing anything, except for scanning this is what happened few minutes back.

1: The rear vent on the pillar (near carboot floor) is indeed giving out hot air just like the front ventilators when the system is on *HI* heat.

2: The roof vents give out cold air, when the system is on *LO* temperature. This is a new change, as previously there was no air at any temperature.

3: The roof vents DO NOT give out hot air, when the system is on *Hi*. Is this normal?

[johnnyroper]

Yes thatââ,¬â,,¢s normal when on heat the floor vent blows hot air, when on cool the roof vents blow Cool air,as far as I am aware roof vents only work for cool.

So previously it did not work like this then? I would just monitor it and see if it carries on working correctly,could be the motor somehow reset or something when you plugged in.

[seatalehandro]

Hello!

So, I am still driving my Seat Alhambra 2003 1.9tdi (AUY).
Of course, it is getting rather old, finally, but I still like it.

In order to pass annual technical inspection, I had to repair a few things (a shop did them).
One of them was a coolant leak at the auxiliary heater (some vertical piping was basicaly rotten).
My aux heater had not been working alread and that is not the main issue here.

Thing is, the shop repaired everything and I passed the technical inspection, but now the luggage compartment blower blows only lukewarm air when on max settings. Thing is, my front blower had died a few weeks ago (started sounding horribliy when finally stopped starting). So...my rear blower was the only thing keeping me warm

Question is, could repairing the aux heater coolant leak somehow have caused this problem? Coolant level is fine. The car was at the shop for 4 days...it is not sub-zero temperatures here yet, but could the thermostat be stuck because of cold or something??

I have contacted the shop, just need to wait a few days before they can have a look.

Thanks in advance.

[Chrispb]

Hows your electric run on pump, if it's not working the coolant flow will be slow through the rear heater.

[seatalehandro]

So the cylindrical thing (circulation pump?!) which usually makes noises after engine is shut off doesnt make sounda anymore


Drive around, got the engine temp to 90..stopped...turned engine off, openes the hood and listened - nothing

Couls that be the culprit?

[Chrispb]

Yes it would also cause the booster heater to overheat if the booster heater was operating due to insufficient coolant flow

[brianh]

Additionally since your booster heater doesn't work, you won't get a decent heat output from the engine alone heating the system when its colder outside. But if your lucky repairing the run on pump and clearing the codes from the booster heater might bring it back to life (at least if nothing else it will help get warmer coolant to the back heater).

I haven't looked on the Galaxy, but sometimes access to the blower motor is possible via the footwells. Yours being presumably a non-uk model will be a left hand drive? Its worth a look at least to see if you can get to it (the horrible sounds you mention sound like some sort of fault with the motor to me?)

[seatalehandro]

Thanks guys.
I drove without the booster heater whole winter last year.

As for the front blower, it can easily be accessed, at least for Alhambra. I saw a video.

I hear though that reading codes foe the AUX heater requires specific SW as in I would have to go to a speckalized workshop dealing with Erbersprachera (spelling ..).

Is there a way to make sure the run on pump.ia dead for 100%? Via a computer diagnostic?

[johnnyroper]

Vcds will Read boost heat codes.

Run on pump just check for 12v at the plug if it has got it and pump donââ,¬â,,¢t run the pump is knackered. Usually brushes worn they only tend to last 80k miles roughly. But itââ,¬â,,¢s cheap enough to re brush the motor.

Got to say the boost heater on mine aided a quicker warm up in colder months but even without it I got decent heat from the heaters once it had warmed. I didnââ,¬â,,¢t find it was essential to have the boost heater to get engine up to temp and decent cabin heat.

[brianh]

The whole pump new can be found on eBay if you get stuck - I replaced mine as it was leaking (or appeared the leaking was coming from it at least, wasn't sure either way as it may have been coming off the scuttle onto it, as also found the thermostat housing was leaking afterwards). Mine came from a German seller for around Ã,£45. But since yours just doesn't work (you'd soon hear it if it did work) its worth a try of some brushes on it.

[seatalehandro]

Ok, thank you for all your replies.
Now, today the plan is to find out how much I can get the run-on pump for and go on from there.

[yeshu26]

Special thanks to Chris and Johhny

The issue is now resolved. Many thanks chaps!

[yeshu26]

PS: I would like to replace my AUX heater since old one is broken (electronically and mechanically). Who is selling one el cheapo? BVK engine code.

[seatalehandro]

I am getting a new run-on pump from my friend later today, it cost me 55 EUR.
As for the replacement, has anyone done it themselves? Would there be much coolant leaking in the process?
I am trying to figure out whether or not I can do it myself later today.

[johnnyroper]

Really easy to change couple of hoses and electrical connection,I used 2 brake pipe clamps on hoses to limit the loss of coolant.

[seatalehandro]

Thank you for the information.
Will definitely report back on how it will have ended.

Just remembered I had bough some diagnostics cable from E-bay, but the problem was on the laptop's end (something fishy about installation)....now I have a new laptop...if I am lucky maybe I will finally be able to at least read errors.

[brianh]

I am getting a new run-on pump from my friend later today, it cost me 55 EUR.
As for the replacement, has anyone done it themselves? Would there be much coolant leaking in the process?
I am trying to figure out whether or not I can do it myself later today.

The worst bit from swapping mine was getting the rubber holders back into their mounting holes - the pump can be slid out of these without removing them from the bracket, do this if you can (as the 15 year old rubber will be hard and not want to go back into the holes if it pulls out, mine had been removed by someone before and bodged back in place with cable ties around the bracket). Not a major job to do at all, just 2 hoses and 1 plug to disconnect, plus little bit of topping up afterwards.

Worthwhile keeping the old one if you intend keeping the car, as the brushes can be replaced at your leisure if you ever need one again then.

[yeshu26]

Blast!!

Windscreen is still fogging/misting. Can someone please share the air-circulation diagram of Sharan ii with me please?
How does the air go out from the car? there must be an egress point.

thanks

[johnnyroper]

Thereââ,¬â,,¢s some vents behind rear bumper if I remember correctly.

Have you checked condition of your pollen filter and also does the recirc flap work correctly on front heater box?