LagondaNet

[peacorp]

Hi Guy's,

I hope you can help.

I have 13085, but its cold inside due to a small fault.

The heating is blowing cold all the time. The system blows hot air to the screen if set to demist but only cold air from the car vents regardless of any settings except off.

So I think it is a stuck flap.

If it is a stuck flap which one would it be, and where would I find it.

If it's not a stuck flap what could it be?.

I have no idea how this system works, so I'm guessing.
I have read all the forum entries on the air con / heating.

Any help would be gratefully received.

Thanks

Dave.

[david]

Look under "Lagonda Restorations", vin 13277 and the posts by Jonathan Clark, it is maybe 2/3 the way down page six.

Otherwise, without any more information, or seeing the car, it could be almost anything but vacuum leaks and/or split vacuum pipes in the engine bay and behind the dash are favourites.

The vast majority of the system is located behind the dash, so a fair degree of dismantling may be required.

David

[peacorp]

[quote="david

The vast majority of the system is located behind the dash, so a fair degree of dismantling may be required.

David[/quote]

Thanks David, you can guess that's just what I didn't want to hear, but I had a feeling that would be the case.

Dave.

[david]

The heater matrix sits on a shelf above the air con evaporator - it is quite a rudimentary air blend system.

The demist vents are located in a top rail above the heater matrix so when you are selecting defrost, an electric solenoid is energised (or de-energised, I forget which) and a vacuum signal is sent to the demist vent flaps and they open accordingly.

If this is happening, it implies that some of the vacuum circuit at least, i.e. from the engine bay into the car, is intact.

It would seem then that the problem is more likely behind the dashboard than in the engine bay and it could be a fault with the programmer or the supplies/signals to and from it - this is located behind the instrument pack and connects to the blend flap by means of a bell crank linkage.

Normally this system fails to heat so you may just be one of the lucky few and find the linkage is seized, but it will still require instrument panel and the left binnacle housing removal to access it.

David

[Vincent]

I would suggest to first check the heating valve on the right side of the engine. We have replaced this part on 4 cars with success...
_________________
Welcome to Paradise ! (FRONT 242)
https://www.youtube.com/watch?v=XS30BC3D5WM

[peacorp]

Thanks Guy's.

I'll have a look at your suggestions.

Dave

[jonc]

[peacorp]

This has been a long time coming, but I have 1 question.

The pipe that comes from 1 on the programmer goes to the water valve, where is the water valve?.

I sent the car away to be fixed and it came back worse. It's my own fault I never let people play with my car but I've been a bit busy so I thought 'just this once'.......well never again!. It came back with hissing comming from the dash and nothing working correctly at all except the fan speed. So I went in to the dash and found 3 pipes disconected 2 of which I have figured out, which leaves the 1 in question.

Thanks for any pointers

Dave.

[david]

Hi,

Port one on the programmer does go to the water valve.

This valve is located in the engine bay at the rear of the right side of the engine bay.

If it is an original fitment valve it will be attached to the chassis leg just in front of where the chassis leg meets the bulkhead, more or less below the wiper motor.

if you still have problems, maybe give me a call.

David

[peacorp]

Thanks,

I'll have a look.

Dave.

[Vincent]

[peacorp]

I have completed the repair so I thought I would report back with the conclusion. It turned out that the programmer was faulty I have replaced it with a second hand unit from the states which only required one hole to be drilled in the flap connecting arm.

The hot water valve is as described here, thanks chaps. That pipe was broken in 3 places so probably hasn't been working for some time.

I have also replaced a few other vacuum hoses as they had either broken or looked like they might soon.

The dash board is a fiddle to get out but not as difficult as I expected and I replaced one of the speedo 7 segment LED's that had lost one segment. I bought all of the stock that an Italian stockist had so I have spares if anyone needs them.

Thanks for every ones help.

Dave.

[RRV363]

I have the same issue. This is of great help. Thanks.
_________________
13372