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Clarky5150

S4 HVAC control dials

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Having now got working aircon I have noticed that, as expected until the vac pump is up to pressure all you get is cold air from all the eyeball vents and no adjustment to the other vents i.e functioning as expected without vac. Once the system is active (for want of a better phrase) and the vent dial is turned it cycles through its various settings however when turned fully anti clockwise to the windscreen symbol only the drivers right hand eyeball emits anything. Its as though the dial isn't turning the full distance. Is there any kind of adjustment possible on this via a cable possibly to get them all flowing?

Also I note that the temp dial doesn't seem to vary the temp much on the footwell, windscreen vents. I get a range of slighty warm to a bit warmer than that. Never cold, never good heat. any ideas anyone??

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I think the heating/cooling system is about as good as the Delco ABS.

From experience, chilled air is only available from the four dash vents, two in the binnacle, two for the passenger. Nothing to the footwell. Make sure all the flexy hoses are where they should be, I had a couple that had fallen off. Sparky also found the diverter flap lever disconnected. I can’t remember the details for the diverter control, maybe someone else can help, but I know there’s a couple of vacuum switches involved cos I’ve changed one before.

Air-con only works when the fan is on. The hot/cold knob is connected via the green cable to a water valve, which is situated up above the pedals. Might be worth seeing if that’s operating fully.

 It’s also worth making sure you have no vacuum leaks. If the GM pump is farting every few seconds, there’s a leak.

I changed my water valve to an electric solenoid, it’s either on or off. As the heater is pretty shit anyway, it actually works quite well.

 

edit - I think the diverter knob has a cable which then controls the vacuum switch/valves.


Margate Exotics.

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Thanks Ian. The trunking is all in place as when I start the car before the vacuum has chance to build I get cold air from all the eyeballs. Once the vacuum is present I only get air from one. Very strange.

As an aside I was contemplating a V8 but read 43 pages of Barry's V8 woes last night. Decided to pickle my own eyeballs instead, seems less painful.

 

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So a quick update. Checked the vac pump run time on the car and its around 30 secs to stop. However if I move the vent Past 3 o'clock the pump starts up again continuously. Before I start taking things apart can anyone suggest which elbow might be responsible?

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Ok got impatient and started stripping. Fairly sure its the heater flap valve. I can see the rotary cam next to it turning but the plunger on the top is not moving. At least its not in a reeeeaaly arkward place to get to!!

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If you’re planning on taking a vacuum valve off, make sure you don’t lose the two screws that holds it in place. Never did find one of them even when I stripped the dash and centre console out. Tiny things, which sprout legs once they’re free.

The rubber elbows go hard and perish after a while, as so many here can attest to. The first job is to fix those vac leaks before you go any further, otherwise you’ll risk disappearing up your own rear end.


Margate Exotics.

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Found it! Took the seat out and assumed the position.

Another 'Lotus specialist' bodge. The lower of the two vac valves has been taken out of the system as has the t piece. The vac pump is only supplying the vent flap which when up to pressure is engaging the flap but when you turn the rotary dial the vacuum has nowhere to be released to so the flap cant return to the eyeball vent position.

Ian. Where does the outlet from the disconnected pipe connect. I can see its another vac actuator on the fan housing but cant see it under the centre console. any clues please?

 

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2 hours ago, Clarky5150 said:

As an aside I was contemplating a V8 but read 43 pages of Barry's V8 woes last night. Decided to pickle my own eyeballs instead, seems less painful.

 

Cheaper and far far less painful


Only here once

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OK, heater fan shroud removed and actuator located. Where the hell am I going to fine 2m off 1950s vacuum pipe and elbows on a Sunday???

 

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The Watford Exotics Vacuum Pipe & Elbow Emporium?

IMAG3164-20190609-130916999.jpg

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British Ambassador to Florida, New York, Denmark and Newfoundland.  And Sweden.

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1 hour ago, Clarky5150 said:

Found it! Took the seat out and assumed the position.

Another 'Lotus specialist' bodge. The lower of the two vac valves has been taken out of the system as has the t piece. The vac pump is only supplying the vent flap which when up to pressure is engaging the flap but when you turn the rotary dial the vacuum has nowhere to be released to so the flap cant return to the eyeball vent position.

Ian. Where does the outlet from the disconnected pipe connect. I can see its another vac actuator on the fan housing but cant see it under the centre console. any clues please?

 

Currently under the Esprit changing rear dampers, but there’s a diagram in the parts manual of where all the pipes go, and the vac valves.

680E8D62-7FC5-472D-86C6-857D8C1F4E94.gif


Margate Exotics.

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1 hour ago, Clarky5150 said:

OK, heater fan shroud removed and actuator located. Where the hell am I going to fine 2m off 1950s vacuum pipe and elbows on a Sunday???

 

Halfords sell them


Only here once

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Not my Halfords Barry. Managed to get some 3mm ID vac hose and that's done the trick. I think the outlets from the Vac valves are on the wrong way round. Luckily I haven't put the car back together yet. Scone and a cuppa time.

That diagram isn't for my car Ian. Nos 18 and 45 are not there.

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OK all plumbed in correctly now but still having issues. Once the valves have been opened and pulled the front flap down for outside air and the vent flap for windscreen demist is engaged when you close the vac valves surely there should be some kind of de vacuuming happen to allow the recirc flap to raise and the eyeball vents to be fed with air?

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1 hour ago, Clarky5150 said:

Not my Halfords Barry. Managed to get some 3mm ID vac hose and that's done the trick. I think the outlets from the Vac valves are on the wrong way round. Luckily I haven't put the car back together yet. Scone and a cuppa time.

That diagram isn't for my car Ian. Nos 18 and 45 are not there.

Sorry about that. To be fair I was in a rush. Best have a look at the S4 parts manual.

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Margate Exotics.

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Thanks for all the help gents, we have a winner!!!

So here is the answer to the puzzle. On a previous repair on behalf of the p.o for which I have the receipt from a 'reputable' Lotus specialist they had taken the recycle flap out of the loop and removed the T-Piece (the elbow at the recirc. actuator was crumbled and obviously couldn't be arsed to skin the required knuckles to get to it.

It transpired that when they put the remaining bits back together they used the wrong vac valve. I swapped that back, reinstated the recirc pipe and T piece but STUPIDLY assumed when said specialist had done the bodge they had at least put the pipes on the vac valves the right way round! The valves have a one way release valve in them and were pressurising but not releasing when the dial was turned.

Escapes diagram proved invaluable and it was only during a passing thunderstorm that I revisited it again and noticed the problem. 

Now fully operational HVAC with Air conditioning

Thanks again to everyone who has interrupted their Sunday to give advice on this.

Better go and get the seat put back in now and go for a well earned blast round.

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