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Discussion Starter #1
Hi folks, I've had a look through various threads on here but I'm none the wiser so far...

My 07 shuttle has a secondary heater in the back (immediately to the right as you open the tailgate), I'm pretty sure this is standard on the SE shuttle. But it doesn't work... Or doesn't seem to. Only cold air ever comes out of the rear vents even though the unit comes on when you press the button. The roof controls all operate, and you can select the airflow direction with the three buttons (they each light up correctly). I've taken the cover off and the white control arm connector thingy is there and seems connected properly.

Any advice on where to look to get this thing operational? Kids are moaning about being cold in the back of the van!

Thanks!
 

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Check the small actuators on the rear heater are moving? They normally sieze so not opening and closing the heater flaps in the back.
 

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Discussion Starter #3
Thanks for the response Keegan! What do they look like? Any tips to free them if seized or is it game over? :)
 

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There were a couple of threads about this a while back.i think the hot water flow os regulated by a valve that is turnrned by a servo or motor type thing.it can be turned manually and wedged somehow.this from memory not experience if you get my drift.ive a vague reccoletion that the valve was somewhere at the front of the unit.guess you'll have to get the trim off and have a fiddle maybe try a google search and preface your search t4 forum as that works better than the forum search
 

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Thanks for the response Keegan! What do they look like? Any tips to free them if seized or is it game over? :)
Late addition to this old thread, but did you have any luck with this?

VW replaced the whole unit on mine (and the auxillary water pump) but I'm sure it was something small like the actuator as mentioned here.

https://www.youtube.com/watch?v=0rsFZkVkrQA

this is from another thread and shows the white plastic actuator arms moving. I think it said the lower white arm going up and down is the temp control.
 

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Discussion Starter #6
Hi six pack- no luck yet- and there seems to be no consistency from where the air flows or whether it's hot ot cold- I can hear the motors and actuarptors moving and they seem to move by themselves too- very strange; I guess I need to get the trim off and have a look!
 

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Hi six pack- no luck yet- and there seems to be no consistency from where the air flows or whether it's hot ot cold- I can hear the motors and actuarptors moving and they seem to move by themselves too- very strange; I guess I need to get the trim off and have a look!
Try: manually operating the temp valve on the rear blower unit with white plastic actuator arm: thus,

I had an issue when I tried to turn the rear air vents to hot for the first time this year just recently but it stayed cold. (The dealer had been in the door doing something and had disconnected / reconnected the wiring plug for the soft door close servo, not sure if it affected it)

I took the trim cover off the rear blower unit by the tailgate, you can see the vertical white plastic actuator arm in front of you that operates the temp valve. Up is cold. The top of the arm is moved by the servo and the bottom of the arm operates the valve to allow hot water to flow [past the heat exchanger I guess].

The servo seemed to try to move the arm when I altered the temp control in the headboard unit, but after a few mm of movement it would return to start position. It needs to rotate around 120 degrees to fully open the hot water valve. It would sit there for about a minute and try again without me doing anything. Again unsuccessfully. It kept repeating this. That told me the servo was fine, power was getting to the unit too.

I set the temp to cold on the headboard unit, and I disconnected the small plastic arm from the servo (you can't operate the servo manually) and pushed the valve down manually (it springs up to the cold position) a few times. I held it down (hot position) and warm air did start to come out of the vents (had the fan on medium). That told me there was no air lock or flushing issue in this ancillary circuit of the cooling system and also that the auxillary water pump was fine too.

After that reconnected the plastic arm to the servo and voila, it all worked fine under the temperature control unit in the headboard.

https://www.youtube.com/watch?v=0rsFZkVkrQA

It's possible that through many months of sitting in the cold position the water valve just seized a little and needed the agitation. Could be the "resistance" made the servo stop trying to force it and hence it would try a little and then return to its start (cold/up) position to prevent some kind of servo overload/burn out.

Give it a go. 10 mins max.

When I had this problem at nearly new the dealer flushed the system, replaced the auxillary water pump, replaced the rear blower unit too and that did fix it (not surprisingly). I do wonder if it was something small like this though (not complaining either !).
 

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Hi All,

So i came across this post regarding rear heaters not working in a T5 shuttle, decided to read it before i took my panels off and see what i was about to find.

Found it very helpful!!

So i took the panel off and BOOM straight away i know exactly why mine isnt working. The little white arm off the actuator has been removed and whatever the arm was ment to connect to on the other end is no longer there, just a hole in its place. also there is a few other bits that have just been stuffed down the side of the heater. Looks like i need to do the old ebay search now and find a new one!!

The joys.
 

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Hi All,

So i came across this post regarding rear heaters not working in a T5 shuttle, decided to read it before i took my panels off and see what i was about to find.

Found it very helpful!!

So i took the panel off and BOOM straight away i know exactly why mine isnt working. The little white arm off the actuator has been removed and whatever the arm was ment to connect to on the other end is no longer there, just a hole in its place. also there is a few other bits that have just been stuffed down the side of the heater. Looks like i need to do the old ebay search now and find a new one!!

The joys.
hi
you should check to see if altering the temperature setting makes the servo rotate (obviously with no white connecting arm it won't operate the valve). that will tell you if the little servo unit is working. If it does rotate then you know the unit is ok and you just need to find the little plastic arm (or a replacement of some kind).
If the servo doesn't rotate at all , or just a few mm then stops/goes back then the unit is trash. It might be possible to find an engineering company to replace the servo unit I guess.
But be warned, this is a common problem, mine was a replaced unit by VW and it went wrong in the same way again post warranty. It seems to be a problem.
I've heard many folks just remove the entire unit (close the coolant loop afterwards). That means a used unit may suffer the problem even quicker than a new one.

Personally I don't see a driving need for the rear unit. There's a fair amount pumped out of the front heater and that one doesn't stop working, but it seems to be enough to heat the whole cabin.
So replacing this may well be wasted money.
 

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Thanks sixpack. The servo moves fine. As for the white arm it's there just led on the floor! Where the end of the white arm connects to is missing. So there should be something sticking out that the arm locates on but instead I just have a hole all the way through the unit. Like you say there is more than enough heat being pumped out by the front heater so I'm in not rush to repair. Will keep my eyes open for one on ebay if someone is breaking a shuttle. Thanks again for you reply
 

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Any one help? Rear heater servo not responding to any changes at dials. Both servo, temp and direction moving a couple of mm in unison every 30s. It’s been unlocked by vcds. Servo changed also (well one of them) and no changes.
Any ideas?
Do I need to take roof lining down? Rear heater turns on fine and responds to changes in fan speed, just nothing else
 

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Any one help? Rear heater servo not responding to any changes at dials. Both servo, temp and direction moving a couple of mm in unison every 30s. It’s been unlocked by vcds. Servo changed also (well one of them) and no changes.
Any ideas?
Do I need to take roof lining down? Rear heater turns on fine and responds to changes in fan speed, just nothing else
Hi
I couldn't quite understand your comment about what was and wasn't working! Are you saying the servo at the top of the white plastic actuator arm is only rotating a couple of mm, then returning to it's original position (upon changing the temperature dial)?
Also, which servo did you change? Was it the one at the top of the white plastic actuator arm? If so, how did you go about changing it as I thought it was built into that rear heater unit?

Then, did you try manually operating the valve at the bottom of the actuator arm (hold it down manually to see if that leads to warm air).
Sorry for the questions but just want to understand where you've got to.
thanks
 

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Thanks sixpack. The servo moves fine. As for the white arm it's there just led on the floor! Where the end of the white arm connects to is missing. So there should be something sticking out that the arm locates on but instead I just have a hole all the way through the unit. Like you say there is more than enough heat being pumped out by the front heater so I'm in not rush to repair. Will keep my eyes open for one on ebay if someone is breaking a shuttle. Thanks again for you reply
Wow, that sounds like the actual valve that allows/stops water flowing [through the heat exchanger] is missing! The bottom of the plastic arm should hook onto that valve. It springs up (cold) in its natural / unsprung position, has to be forced down for heat.
Are there bungs in there or something to stop the coolant coming out? Would be interesting to know how the coolant is staying in there since you would expect the valve to be inline ie the fluid to flow through it.
 

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Wow, that sounds like the actual valve that allows/stops water flowing [through the heat exchanger] is missing! The bottom of the plastic arm should hook onto that valve. It springs up (cold) in its natural / unsprung position, has to be forced down for heat.
Are there bungs in there or something to stop the coolant coming out? Would be interesting to know how the coolant is staying in there since you would expect the valve to be inline ie the fluid to flow through it.
There is no water valve, the heater matrix is full flow all the time, the temperature is controlled by mixing air through the matrix and cool air straight from the vehicle interior, the servo just moves a flap. There's no fresh air from the outside to the rear heater.
 

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Yes both the hot air servo and direction servo move a couple of mm in unison then return to the initial position. Neither moves as directed by the switches.
ive disconnected the white actuator arms and moved them manually, they are fine.
one servo changed (hot air) and still does same thing.
vcds says no faults. the motor seems fine as responds to fan speed switch etc. only issue is it not moving servos properly.
is there something I have missed?
 

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Yes both the hot air servo and direction servo move a couple of mm in unison then return to the initial position. Neither moves as directed by the switches.
ive disconnected the white actuator arms and moved them manually, they are fine.
one servo changed (hot air) and still does same thing.
vcds says no faults. the motor seems fine as responds to fan speed switch etc. only issue is it not moving servos properly.
is there something I have missed?
For me, the valve that changes the temperature moved up and down fine manually (and affects the air temp as expected) but the electrical servo that rotates could not be operated manually (it just does the couple of mm movement electrically and then returns/stops). I'm surprised you were able to operate that servo manually - were you really able to do that?
Assuming you can manually rotate the electrical servo, I'm not sure if that's a good or a bad thing! Maybe it seizes when faulty or maybe it moves freely when faulty. I'm not sure which! Perhaps a check on the voltage coming to it if the wiring plug is obvious? Perhaps an electrical engineer can check the servo itself, dunno, sorry.

At this point for me, VW replaced the entire rear heater unit (having flushed the system and replaced the aux water pump) while it was all under warranty. That of course fixed it but the problem came back (now) with the replacement unit after a few years.
I don't see the servo as replaceable but the poster above says his servo is missing with a hole right through the unit, so maybe it can be if you can get Delphi to supply you with one.

At the very least it's worth a complaint to Delphi that they've a manufacturing issue. Loads of folks have this issue and it's that stupid little $3 servo that seems to fail. VW aren't interested due to age but also because they only deal with the entire component part.

At least it's not really a big issue in the cabin as heat from the front is generally sufficient.
 
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