Air conditioning not cold

[TheTree]

Hi

I have an issue where my Air con has decided not to get very cold. Last Saturday the exit pipe from the compressor was very cold and had condensation on it but now it's decided to not get very cold:(

The compressor clutch is engaging and I am 99% sure it has plenty of gas.

I read on rr.net that it could be the Tri-state switch. There is also some kind of pressure switch on these earlier models.

As far as I can tell the expansion valve might be the culprit as well.

Anyone got any ideas before I start throwing money at it !

Steve

[DieselLSE]

Hi Steve, one or more of the blend motors may be part of the problem. But with a 20 year old aircon system it could literally be anything or a combination of problems.
My advice would be to get it diagnosed with a test unit to see what fault codes it throws up.

[TheTree]

Hi Steve, one or more of the blend motors may be part of the problem. But with a 20 year old aircon system it could literally be anything or a combination of problems.
My advice would be to get it diagnosed with a test unit to see what fault codes it throws up.

I am thinking along those lines as well

I have replaced all the hoses and the condenser and receiver drier about 9 months ago, so I know some parts are good

It's not showing any codes in the nanocom, so perhaps it needs to be hooked up to a more specialised machine

Thanks
Steve

[mtb_gary]

Steve

I am also of the opinion that professional help may be needed here. The trial and error method can get very Costly! The fact that you state that the condenser is not getting cold I would have thought lack of pressure. Thanks A/C specialists can do a these for gas. It may be a leaking hose are any other component as far as that goes. The clutch is engaging but is there any chance it could be slipping? If you have any spacer shims on q the clutch you could try removing one and see if it rectified the problem. Other than that seek professional services.

Good Luck!

[banarcus]

Well what a coincidence. I bought some 2nd hand HEVAC servo motors from pommyland, a TX valve from work and some Hychill minus 30 from Bursons.

I'm halfway through the job with some emergency home made heater core orings (tested 100% OK) and fitting the dash back in.

Mine had the same symptoms as Steve and it was low on gas as I had a leak in the evaporator. It was a very gradual decline with that pungent stink from the air con oil coming through the vents.

I'll report later on today.

[banarcus]

Well I can say that the re gas was a success! This Hychill stuff is very much like the old R12, I've never had a later model car with such cold air before.

Sorry for the slight hijack Steve.

[JohnnyB]

Hello Steve
If your problem was in the control system i.e. Trinary (tristate) switch the clutch would not be pulling in. Are the condenser fans in front of the radiator running? Is there air coming out of the vents? Is the dreaded A/C symbol displayed on the A/C control panel.

[rick130]

Something's not right if the clutch is pulling in and the suction line isn't cold and sweaty.
At the same time the liquid line should be a bit above ambient and the discharge line too hot to touch with a few revs on the engine, fan set at high.

You need someone qualified to put gauges on and see what's happening. Without them you are blindly guessing.

[TheTree]

Thanks for the comments everyone, we had a good look around all the wiring etc and there is nothing which appears to be out of place.

Definitely time to get a professional to look at it. It was cold one day and not the next, in typical P38 fashion it decided to wait until the weather got really hot before it stopped playing !

Steve

[TheTree]

Hello Steve
If your problem was in the control system i.e. Trinary (tristate) switch the clutch would not be pulling in. Are the condenser fans in front of the radiator running? Is there air coming out of the vents? Is the dreaded A/C symbol displayed on the A/C control panel.

Hi Mate

Yes all those things are working it correctly, I do have the chequebook symbol but that is the left hand reticulation motor (the fresh recycled air one)

Regards
Steve

[Scouse]

Hi Mate

Yes all those things are working it correctly, I do have the chequebook symbol but that is the left hand reticulation motor (the fresh recycled air one)

Regards
SteveWhen you get around to replacing it, fit an O/S recirc assy which will place the motor on the inside. This means it's easy to access by removing the glovebox instead of half the dash.
I swapped both of mine around while I had the dash & frame out but found the O/S is still a PITA due to the frame now blocking it.

[TheTree]

I finally got around to contacting my mobile air con guy and he is going to drop but tomorrow and have a look.

He suspects a slow gas leak from either the compressor seal, TX Valve or evaporator. So he is going to top it up and we will see if we can nail down the leak

Steve

[TheTree]

Hi

Well she is still full of gas and the way it is behaving it seems it's the TX valve playing up. Luckily it can be replaced from under the bonnet, so no dash out :p

I asked him about Hychill and he said it's a better gas but because it has smaller molecules it's harder to keep in the system. He said he started using it on P38's and found he had to come back and refill them with r134a after a few months.

Given that I have new hoses I think i will give the hychill a whirl when I replace the TX valve.

I am wondering if I should also replace the Tri-state and low pressure switches while it has no gas in it. Not sure about the long term reliability of those switches

Steve

[DoubleChevron]

Hi

Well she is still full of gas and the way it is behaving it seems it's the TX valve playing up. Luckily it can be replaced from under the bonnet, so no dash out :p

I asked him about Hychill and he said it's a better gas but because it has smaller molecules it's harder to keep in the system. He said he started using it on P38's and found he had to come back and refill them with r134a after a few months.

Given that I have new hoses I think i will give the hychill a whirl when I replace the TX valve.

I am wondering if I should also replace the Tri-state and low pressure switches while it has no gas in it. Not sure about the long term reliability of those switches

Steve

I've always heard it's the other way around. Hychill leaks a lot less ... due to the lower pressures it runs and bigger molecule size. Someone else will look it up for me :p :wasntme:

seeya,
Shane L.

[TheTree]

I've always heard it's the other way around. Hychill leaks a lot less ... due to the lower pressures it runs and bigger molecule size. Someone else will look it up for me :p :wasntme:

seeya,
Shane L.

From what I can see hychill has bigger molecules so as you say it should leak less.

Perhaps the old hoses just aren't up to the job anyway, mine were leaking very badly before I replaced them

Steve

[andyaa]

Hello all - I too have a similar problem but pretty sure I have no faults showing. Can anyone recommend a good outfit in Melbourne who knows these cars?

Thanks

andrew