Talk Morgan Forums Morgan Sports Cars Classic Morgans (pre-CX) Trad Air Condtioning

Thanks Jon already done that and satisfied myself all is ok. No drains blocked, no drain tubes trapped.

Richard. If there is a main wiring loom grommet above the driver's footwell (RH side) it may be worth checking that water may be getting under the ECU cover (if that is where it is on your car) and dripping past the grommet. That is why I put a neoprene seal around the ECU cover flange.

Water dripping down may give the impression it is blowing out of the heater/aircon vents.

Thanks Peter but no leaks there and I keep a regular eye on grommets which can work out with vibration and jolting. I don't have an issue with odd spots out of vents either it was just an observation.

I respect disagreement. So thank you for yours. But my fix is so common sense. Additionally, it has worked over and over and over again with later AC Morgans.
The AC instantly becomes what you would expect from a normal air conditioned car. We can argue about rationales but a de facto solution is always to be respected.

It also stops the condensation that drips into the foot wells or wherever. (the fact of water adhesion means that the dripping can be anywhere under the dash.)

That same condensation, after it has begun, rusts the controls, which could be the cause of your hyper stiff vent control. Rust, grease and dirty does not help its movement.


That being said, I am with Luddite. Extraneous add-ons, unnecessary to power, aesthetics, comfort, braking or cooling are not of a keen interest to me. They make the cars harder to use and maintain. However, if I am asked to help a mogger achieve want he/she wants, I have be known to point out the obvious.

Why don't you take a 10 quid risk and try mine out?

gmg

Dear me!
As a matter of observation (without even considering science) I have never seen condensation on the outside of a cup of hot tea but I have seen condensation on the outside of a cold glass of beer.
This would lead one to believe that condensation is not possible on the ouside of a hot heater element so if there is water in that zone the cause must be looked for elswhere; ingress of rain water, leaking washer tubes, or leaking from the engine cooling/heater system.
On the other hand all aircon systems condense water out of humid air, just like that cold beer glass, that freezing cold element is the evaporator and part of the effect is to remove humidity from the air, that is why drains for the condensed water are important.
I can assure you that after 10 years of use there is no rust on the heater control quadrant (behind the knob on the dash). If any water ever got there I would be looking for leaks higher up. The cable and the movement inside the airbox where perfectly free but the mechanism behind the dash had been assembled too tightly from new and with dried and hardened grease had become almost impossible to turn the knob.

Now to forget about aircon for a moment and discuss hot air entering the cabin; I have already mentioned the problem that the top of the airbox. From some time in the early 2000s the seal to the underside of the bonnets was changed from 2 rectangular forms, made from a rubber extrusion, either side of the bonnet hinge to an incomplete closed cell foam seal. See previous photos. Closing the gap stops hot air directly from the engine bay entering the ventilation system. None the less the design of the Morgan bonnets still means that some hot engine bay air exiting the louvres ahead of the air ventilation louvres may still enter. A better solution may be to have no top louvres on the bonnets except those dedicated to the ventilation system.

If hot air from the heater element , with the more recent trad system, is entering the cabin when not desired there are two possible reason: 1. the heater control flap is not closing completely, or 2. the hot part of the airbox, with the flap closed, is not sufiiciently insulated from the cold air chamber.
In the case of the first it may be possible that the control cable needs adjustment otherwise there must be a mechanical fault inside the box. The second issue, if there is insufficient insulation of the internals of the box (quite probable), would be much more difficult to fix. In that case Lorne's idea of a cutoff valve is quite valid however, ideally, it should be a solenoid valve linked to the dashboard heater control system. The reason for this is that a combination of hot air and air dehumidified by the aircon system is often desirable to dehumidify the inside of the car in cold rainy weather. Even with a non aircon car there would be times that you would not want to be fidling under the bonnet to get hot air.

I am somewhat inspired to experiment with a valve although I have to say that my experience is that blocking hot engine bay air from entering the top of the airbox makes a big difference.

Not an appropriate analogy


Much better. One merely has to examine a home air conditioner, a window, wall, or central unit. They do not produce condensation in the UK? (Of our 4 months of annual mogging in Europe, we were never there for the summer months!)


Gambalunga, my thoughts on this subject (almost two decades ago) address early overseas AC Roadsters. The wide spread rusting control complaints came from that crowd (the Roadster forum). Don't shoot this messenger. I merely followed LOGIC and the valve operated cabin heating systems from Morgans from the later 1950s to 2004. It is obviously unwise to run AC cooled air through a heated place adjacent and above a constantly hyper-heated heater matrix without a shut-off valve. If you think that has no effect, so be it. I am not a retailer. I haven't advertised or a accepted advertising in 30 years.

It is people like yourself, with much later Morgans, who have told me the system never changed..which astounds me.

Lastly, overseas stock Roadsters had AC long before they became common anywhere else. Much more experience I imagine. And the UK has very different weather. Much damper and cooler ambient conditions. Australia and the southern US weather are quite different from the UK. So the fault will express itself differently. As I said, the simple fix never fails with owners in those parts of the world. Nothing brilliant in any of this. Merely common sense. It is also my observation that common sense is a much lower priority for auto manufacturers than government regulations. There is no laws I know, worldwide, the require the latter any more.


All trad owners have problems with that. A few obvious factors come to mind.

1. The cutoff of the coolant into the heater matrix is inadequately handled by the traditional valve. I changed mine to an electrically operated solenoid shut-off. That worked.

2. The constant flow of air into the heater system from the engine bay, is AS YOU SAY, a problem. It can be cured in many ways. The simplest is to block that inflow with a piece of cardboard used as an air dam. (tedious) I found the solenoid valve sufficient..that being said I have heat reducing ceramic coated manifolds and down pipes which muchly reduce engine bay heat.

3. The cabin heat is effected, (again muchly) by un-insulated firewalls and too thin insulation of the gearbox cover. (the gearbox area is designed in such a way that it traps hot engine air flowing under the car). I swapped out my firewall carpeting for insulated carpeting and though I have the same gearbox insulation as you do, I insisted on 1/2" rather than 1/4" padding on my gearbox leather. Unlike my earlier Morgans, we can rest our legs against the gearbox regardless of weather on the hottest day.


Smart man. I imagined a solenoid valve connected to the control system, though I never bother to think of the details for that. Turn on the heat, and the hot coolant flow would be opened to the matrix again.

I am somewhat inspired to experiment with a valve although I have to say that my experience is that blocking hot engine bay air from entering the top of the airbox makes a big difference.[/quote]

No need to do much to see if the idea works. Merely join the matrix in flow to the outflow. with a cheap joining pipe of the right size. Your matrix will drain on the floor, but you can add the small bit of coolant lost to the system when you run it to stock. A cheap plastic joiner will cost you about 1 pound on Amazon.uk.co. Be great if you could test the relative AC effect and humidity, before and after. IN any event, assuming you DO have the same system as the one's I have seen, it is hard to argue with success.

Good luck.

gmg