Talk Morgan Forums Morgan Sports Cars Classic Morgans (pre-CX) Air condtioning query

Well, on my 2005 3.0L Roadster (US spec the AC condenser was fitted below the engine.) I move the condenser to the front of the Radiator. I also recharged my AC system with the latest AC refrigerant. Relocating the AC lines allowed all the cold gas to leak out so it had to be done. I also move the vents to the bottom of the dash so that more than just my knees would be cooled. See pic.

Cheers,
Mark

Had mine fixed this morning. Friendly "while you wait" service (40 mins), it's great to have some cold air again, not Arctic, but colder than it's been during my 5 years of ownership.

The problem with A/C on a Trad is when you turn the heater control to cold it doesn't stop the hot water from going through the heayer box, the cold air from the A/C goes through the heater box so you cant get really cold air into the cabin. Has anybody solved this ?

My AC is a pair of aeroscreens so possibly showing my ignorance, but couldn't you put a manual tap in the feed to the heater matrix? ... work of moments to isolate the heater on hot days or vice-versa ??🙂




K

Rather than cut off the coolant flow through the matrix, which might cause unexpected coolant sensor issues, it would be safer to have a by pass between the input and output pipes. I'm visualising two T Pieces, with a tap on the by pass. So tap closed is as it is now, top open would allow coolant to by pass the matrix, although a second tap on the inlet pipe would ensure no flow completely. It's certainly do-able. Might even be worth it without AC.

As expected ..... showing my ignorance 😆 .... comes from having a car too old for AC and therefore mercifully free of demon sensors!! .... don't need a sensor to tell me if my heater's working ... my MK1 calibrated shins so the trick😆

K

I can save you time. The schematic is something I cobbed together for GoMoG many, many years ago That systems is not very smart. It places a heating system one cannot shut off next to a flow of cooled air. The result, as you can well imagine, is at best a damp humid flow which is non-ideal and rusts the internal control. I was encouraged to look at it, though I am not a fan (PUN!) of Morgan aircon. The unit was designed by a small aftermarket firm in the UK. Unlike most Morgan suppliers, they were unhelpful, but it is not hard to see where they went illogically wrong.

1. one can merely use a mechanical or solenoid controlled shut off valve that shunts the unwanted hyper-hot coolant away from the cabin matrix when using the air conditioning. In fact, I adopted a solenoid device to use to stop the hot flow to my non-AC system rather than the tortuous clutch cable pre-AC cars are fit with. Works a treat at the press of a button.There are many other automobile companies that use the gomog system. BMW is merely on of them.

2. one can rip the entire system out and replace it with something smarter. Many have done so. There will be no loss as your internal controls are probably rusted out anyway and the system is designed to fail.

https://www.gomog.com/allmorgan/CabinHeaters.html#BETTER

Lorne.

Thanks Lorne, I had not seen that particular wisdom before. ".....air conditioning fighting with heating using the same distribution system" summarises the root cause of my less-than-Arctic air, and should be essential reading for any owner of an earlier Morgan with A/C. So although I'm now happy(er) with my Roadster's A/C, I am aware of the system's limitations. Perfect it is not, but I hate having anything that just doesn't work: I fix what I can myself, but seek professional advice and service when required.

It's not a single feed and it is part of the circulation system, you can't just shut it off easily. It looks like it would need 3 taps and a bypass pipe. Probably be easier
to Aberdeen where I wouldn't need it

Lord, This is an issue one finds when outsourcing design. The older cars placed a shunt between the two coolant hoses going in and out of the heater matrix. (for those unfamiliar with the term "heater matrix" it is actually second little radiator that is heated by the coolant flow. Air is forced through it, it becomes hot, and it is fan pumped into the cabin. Sadly, all these system push air into the cabin contunally, pushed by the air intake.

In those days, when the awkward old coolant flow cable is shut, a bypass, the old one below, was placed that moved the flow from the matrix to the return pipe and circulation continued. That was important as without circulation at all times, the water in the cabin heater system keeps getting hotter and hotter. Over time, both the Factory, non-savvy dealers and owners, forgot the purpose of the bypass, left it off, and kept the cabin hot. Your system is the worst as it has no shut-off nor bypass.at all! See below.

You need a shutoff to the matrix AND a shunt to the return hose. I use one as I dislike the poor function of the earlier cable, another weird one.. So I use a solenoid operated shunt and shut off. In your case, you have nothing so it is much more than a case of convenience. You can use any of those used by Audi, Ford, GM,Mercedes, Jeep, BMW, Volkswagen assuming they still use them. If you connect to the aircon on-off, it will sort the hot coolant flow automatically. It will, of course, not interfere with anything. I have been using mine for 15 years on a EFI vehicle. It is the last thingie below. The flow to the coolant temperature sensors is unaffected

Your difficulty is access. As time goes on, our engine bays got more and more crowded. I helped people out with this issue, You will have to remove a few hoses for easy access.

Lorne