Talk Morgan Forums Morgan Sports Cars Morgan Plus Four, Supersport & Plus Six (CX & CXV Generation Vehicles) Air Conditioner problem

I have a 2025 Plus Four and have a question re A/C that I hope you can help.
When the A/C is on and the temperature is turned down, the cold air that comes out is replaced by warmer air( not as cold) then after a minute or two the cold air is back and the cycle repeats. Is this normal or do I have a problem.
Thanks for any help.
David

Sorry to hear about your problem. I have not noticed this issue on my Plus Six, which I assume has similar system.
You write about the temperature control knob that you turn to low. Perhaps, obvious, but as you didn’t write about it: do you turn the fan speed up and have both airvents at front open?

Yes I do all of that. But the air continues to cycle between cold and less cold/warmer air.
Thanks for reply.

My Plus Six had that issue; at the same time the light on the aircon switch would flash, rather than show a steady light. I got it fixed by MMC at the service, it simply needed re-gassing.

Ours also cycles between blowing very cold to slightly less cold, if you listen to the engine you can time this to the air con compressor activating in and out. I believe this is a normal function in the system design ref its sensor response time .. the time between cycles is fairly short. Our system has always done this even when regassed. We had an issue when the car was almost new of losing gas, the main dealer chased this on and off for almost 2 years, in the end the pipes seals were replaced, as high hamster says when the gas has leaked out the aircon button light will flash. Since the seals were replaced its worked as described. We tested it out in France recently in 38 deg in shade heat and it performed ok.
If in doubt about your cars system let the main dealer have a look at it.

My 2023 P4 has the same issue the a/c cycles between blowing cold and not so cold. I asked my main dealer about the issue and they checked that the pressure in the system was ok. It was. The explanation given I am told by MMC was that as the interior of a morgan does not have a thermometer attached to the system to switch the a/c on or off when the desired temp is reached the system is on a simple timer. This switches the cold a/c on and off in a cycle as we are all experiencing. I am also told MMC were asked if there was a fix, the reply being they would look at it! Surely the simple and easy fix would be for the compressor to be on when a/c switch pushed in and off when out?

Retrofit a cabin thermometer into the control unit for the a/c ?

My plus 6 has been blowing cool for a while now think i need a re gas, does anyone know which one it is. I used the Halfords DIY jobbie last time on the tin top but I think I will leave the Mog to a proffesional.

Aircon design can be tricky and it needs a specialist design engineer. Its not as simple as just leaving the compressor running, as the system has to be in a balance or it could freeze up and/or cause mechanical damage to the compressor. If the MMC went the route of a simple system, then I would imagine its been designed to operate in a manner that will provide a limited aircon and keep the aircon running when the operator has the top up or down, as in one case you have a closed area and in the other an open area.

Morning Em, cant help ref the gas type I am afraid, I was going to ask about this as well, so if you find out please can you let me know. The gas now used in systems has changed since my days in aircon involvement..
dave