Xantia heater not working cold air flaps/blower

[Stickyfinger]

1993 car, No Aircon
No heat.
Water flow in In/Out pipes is hot, rad top hose/thermostat are good
System flushed/bled well with raised header tank/burped etc.
Heater control sliders work (I can hear a change in tone when I slide them with fan on full)

After discussion with Jim I think we are down to two options, either the cold/warm flap is not working/broken or the ducting is blocked (mouse house/debris ....)
The plan is to try and get access to the system as much as possible with the understanding that full access can only be achieved by removing the dash. (summer job)

My questions....never having done such a job let alone on a RHD car......and as it is cold good guidance will save time thus limit the chance of hypothermia/wood burned in the garage stove = save the planet/keep Ed Mini-Brain away)

?? Best way to access the blower motor
?? Can I reach the flap control levers by hand...best way to access them
?? Am I correct in thinking a NoAirCon car will not have a pollen filter
?? Will removing the blower motor give access to the "outside air" side of the ducting
?? Can I access the inlet vent under the scuttle WITHOUT removing the delicate and most probably very brittle plastic windscreen/scuttle moulding.

Cheers chaps

[Clogzz]

The pollen filter may need replacing.

[wurlycorner]

either the cold/warm flap is not working/broken or the ducting is blocked (mouse house/debris ....)

I'd have thought if the flap was broken/not functioning, you'd get heat OR air-con, but not neither?

Sadly as it's RHD car, my direct experience from dismantling an Activa to break, isn't very relevant.

From looking at the parts diagrams, do they use the same heater/a/c unit on LHD and RHD cars, or is it a different one?
If different, then it would be reasonable to expect it's a mirror image and in which case, Haynes would still be relevant and i.e. blower motor easy to access and remove (sadly Russek doesn't cover anything interior/heating etc.)

[peter306]

Hello Alasdair,
If it's the same as a 1.8 then the glove box needs to come off, that allows access to the blower motor screws, with that out of the way you should be able to see the exterior/recycle air flap.
After removing the bit of carpet under the glove box you should be able to see the flap lever, assuming it's in the same location as a powered one, may be an hands and knees job to actually spot it, I was kneeling on the ground with my body in the footwell to get to mine.
Rgds Peter

[Chris570]

Might I suggest one of these https://www.amazon.co.uk/Endoscope-Insp ... r=8-7&th=1

if you haven't already got one of course. Very very useful and should tell you all you need to know. I'd happily lend you mine, but with postage it makes sense to just buy one.

From an experience POV, having done the dash out twice on a RHD activa, it's not that bad.

[xantia_v6]

Pollen filter was only fitted with A/C.
One of the heater controls (I think the hot air flap) is situated on the bottom of the heater box with the flap axis running vertical, so access is severely hampered by the presence of the floor... Best access by removing the centre console.

[Stickyfinger]

Cheers for that info.....looks more and more like it will be a summers job then if there is no debris in the accessible pipe work or the flap starts to work by pulling on it/pushing on it from the controls end.

[wurlycorner]

Hang on... RHD :facepalm: as in UK car - I didn't have my head on and seemed to recall from the dim/distant past that you had a French import Xantia!
The dash is absolute pita to remove. Haynes is good for pointers, but I seem to recall it missed some of the bolts needed from under the scuttle?

[Stickyfinger]

LOL.....yes it is a UK car.... I also now have a lowly Pov spec 1993 1.9TD sinker Xantia to go alongside my V6 "French (Left) Hooker"

Dash out= PITA it is...hence a summer job and thus I will wear a coat and thick socks IF I do any long trips in the 1.9

[wurlycorner]

That makes sense - glad that I wasn't imagining the left hooker!!!

[Stickyfinger]

TBH that dash will also need to come out at some point as I have a "swelling"which is distorting one of the demister vents .....but there is no rush on that

[Stickyfinger]

UPDATE:

I have dismantled the front of the dash.....pulled/disconnected the cables from the mixer control slider.

I have pulled/pushed all three air-flow cables and they all work, I CAN hear the flaps "thud" closed/open and with the blower motor running they control the air flow enough to blow off a rubber glove.... so I am assuming that there is NOT a blockage or stuck flap on the air-flow side.

I then put my hand behind the engine and felt the heater matrix flow pipe............both LUKEWARM by feel....but my temperature measurement gun is out of battery power !! bugger !!

The heater control cable also is easy to push/pull and a thud is also heard so that selector flap is also working.....moving the control cable gives LUKEWARM air which confirms the lukewarm matrix supply/flow pipe temperature being low.....

So, my thoughts are that it is =:
NOT a airflow blockage
NOT a cable problem
NOT a flap problem
NOT a Airlock (as there is water flow giving lukewarm heat)
-----IS a water flow problem through the matrix..as the car has sat for years

The next step (unless anybody shouts STOP you IDIOT) is to get some Fernox F3 system cleaner in it, run it for a few days with that in then re-flush.

https://fernox.com/product/cleaner-f3-500ml/

[RichardW]

The matrix was probably leaking but now it's not 'cos someone has filled it with radweld!! My guess is if you disturb it / try to clean it out, it will leak.

[Stickyfinger]

There is no evidence the matrix has ever leaked, there was no "substance" visible in the system when flushed.......but yes you are correct, that will be the lottery ticket.

If it happens then it will get some more rad-seal until the summer

[wurlycorner]

Yep, worth trying some rad flush.
If you have access to an airline you can also get a water hose gun that has a fitting to accept compressed air and you can use that to help flush the crap out of the matrix.
Eg:
https://www.ebay.co.uk/itm/225975735574
They're really good, especially after using a descaling agent.

Obviously as we all know, Xantia matrix are unfortunately a leak disaster waiting to happen but... Good luck!