Hello, is anyone familiar with manually setting the blower direction? Currently, I have a broken servo, and the vents/defrost will only blow cold air, making me believe the blower is routing air over the evaporator rather than the heater core. Until I have time to replace the servo, I would like to force all air over the heater core and out the dash/defrost vents. I have hot water going in and out of the heater core.
Is it normal to only get the hot air out of the defrost vents? That is how my heater has always functioned.
To be clear, it is intended that all incoming air is first refrigerated via evaporater and then heated as necessary via the heater core
The servo can be unplugged and then driven (using a 9 volt battery, typically) to any operating position by applying voltage and ground to the red and purple wires. Be careful not to over-rotate the servo. (Someone here will double check me on the wire colors. Iām on my first cuppa coffee)
But, if the servo itself is non-operable, this wonāt be possible. In that case youād have to figure out a way to manually operate the flaps and hold them in the desired settingā¦which probably wouldnāt be that difficult
Yes. Defrost mode defaults to max heat and highest fan speed
Hi @Doug_Dwyer! Youāre always a wealth of knowledge. I donāt believe I have ever achieved hot air out of the front vents. Is that normal?
Also, do you know where the flap is that would prevent heat from coming out of the vents in its current state? I havenāt seen any good diagrams on how the air routes through the climate control system.
Outboard vents at each end of the dash? When the system is in āheatā mode most of the hot air should come thru the footwell vents with a small amount coming thru the L/R dash vents.
In ācoolā mode most of the chilled air comes from the center dash vent, with small amounts from the L/R dash vents.
When the system is in blend mode youāll get most of the air from the L/R dash vents. In blend mode the air will be warm-ish or cool-ish, as the system uses āblendā to maintain selected cabin temp after āheatā mode or ācoolā mode has done all the work, so to speak.
For this weād need the factory service manual or the Delanair training manualā¦the latter of which I think someone has copied to PDF and can send it to youā¦if they see this thread. Either one shows the various flap locations very well. It would be difficult to describe verballlyā¦for me, at least.
Going back to your first postingā¦
Can you elaborate at bit? Is the servo flat-out dead or what?
[quote=āAdam_Thompson, post:1, topic:426940, full:trueā]
Currently, I have a broken servo, and the vents/defrost will only blow cold air, making me believe the blower is routing air over the evaporator rather than the heater core.
[unquote]
The question raised by Doug is very pertinent, Adam - is the servo actually broken. The usual problem with a stuck/non-moving servo is a failed AC amplifierā¦
As Doug implies; connect the red and purple at the AC amp connector with a battery. The polarity decides which way the servo motor turns. This will at least verify whether the servo operates, or not. If it does; your problem is the amplifier, and the servo can then be easily controlled - there are conversion kits for thisā¦
The problem is that the servo controls all functions of the AC system - without turning the servo nothing actually works. In this case; cams on the servo operates pushrods to move the flaps that directs air trough, or past, the heater core. Physically turning the servo by hand, you can see the related action on the external linkages.
Which is not a practical way of controlling cabin heating - but may afford a temporary relief. If the center vents are open the servo/amplifier is stuck in ācoldā - and it may reset to full ācoldā if the AC amp is connectedā¦
As an aside; the side vents always has the temp set by the servo/amplifier - only the flow and directions are manually controlledā¦
When one considers this was the First Fully Automatic climate control system, well before any fully electronic magic was available, back when one had to manually open or close the heat valve with a lever and cable, and pull vents open or closed individually by hand, the fact it works as well as it does is a Marvel. And I imagine when it first hit the market it was a Stop The Presses moment!
Yes itās a bit cumbersome, but thatās part of its charm.
(ā;ā)
Not the first Auto Climate Control, LnrBā¦although the first for Jaguar, if thatās what you meant.
GM, and perhaps others, started offering auto climate control in the 60s on the higher-end models. I wanna say 1964 or so. Mightāve been earlier. They, too, could be tricky to repair.
I must say that itās a so-called luxury feature I could live without. I donāt feel that my comfort or convenience is compromised by having to (oh my god) manually adjust the heat/ac settings
The automatic vents selection is not that bad, you want heat at the lower vents, AC at the fascia vents on the console, and defrost/demist at the dash vents.
And this is what the system does.
The only problem in my books is that you get hot air from the dash vents only in defrost mode and then the system goes on full heat, very problematic on a warm rainy day.
This was my solution to this.
Other possible and easy modifications are to add switches for the AC (Napoli mod), the blower fans (Bernet mod) and the Recirculation flaps, while keeping the climate control active.
A lot of thought went into the set-up, Adam - basically to ensure cabin comfort at all times. Designed for rapid cabin heat-up and cooling, and for stable cabin temps when reached - and working as it should; it doesā¦soā¦?
All operations are directed by the servo cams, and slaved to the position of the servo. There is no problem removing the AC amplifier, eliminating the temp control, and controlling servo movement with an electric switch. But flap settings etc are still controlled by the servo - no independent control of flaps, or indeed the heater valveā¦
Elimination the servo for manual control of all functions will indeed be cumbersomeā¦
Iāll need to look at the mods @Aristides mentioned. I also have the issue where my windows fog due to rain, and AC would seem more appropriate than heat.
Indeed, Adam; the important thing with the AC is that the cold evaporator dries out the air. With the system in āheatingā the air is recirculated - but with rain, the screen is still cold enough (dew point) to fog up the screen with residual moistureā¦
In āDefā, wet ambient air enters and may not be adequately dried - and the cold screen cause fogging. The same applies under normal driving - to some extent it relates to screen temp. But permanent fogging is abnormal - the screen should clean up after a whileā¦?
Itās safe to say that for my XJ is not in the best shape. The AC is mediocre and the fan seems to only work well on high. Lastly, the wipers move at a snails speed. I switched the servo to be manually controlled with a toggle switch. All that being said, I absolutely love the car and like to use it as a everyday driver. The climate control system leaves me in a constant state of frustration. Thatās why I was wondering if a total upgrade might be a fun upgrade.
Obviously the system is not working as it should, Adam - which sure will cause frustrationā¦
It may be easier to restore it to original function - a total upgrade is serious business. As an aside; the fan speeds are controlled by a bank of 4 relays, operated by microswitches. Failure of any speed may lie thereā¦?
And on a dry screen, the wipers are indeed woefully slow!
Maybe low on refrigerant?
In Kirbyās Book there is an extensive chapter on the AC and how to adjust the flaps for optimal performance. Worth giving it a read.
There is lots of air flow, even on low speed. Itās just that with so many outlets itās not that apparent, and most importantly, itās designed to be very quiet, you canāt blame it for thatā¦
Once sorted out it works very well Adam.
And with the modifications I did, itās perfect.
Thatās a common problem.
Installing relays will transform them.
Same with the electric windows and headlights.
All the details are in the Book.
Iām not entirely clear on what youāre saying but wanted to mention that poor connections at the relay pack can cause mysterious problems.
Over the years some guys have ditched the original systems entirely and installed aftermarket. The results seem to be good, but such as job is neither cheap nor easy. Itās a big project.
The Delanair system is tricky but, personally, I wouldnāt be too anxious to dump it without first checking for the easy fixes: poor connections, a broken vacuum line, etc.
I much prefer the S1 system:
No whirring, cool air outlets to the face, individual adjustments for driver and passenger (feetā¦.windshield) , and a simple hot and cold adjustment. The heat compensates for coolant temperature.
And a recirculation/no air lever. I tell it what to do and it does just that immediately.
