Philo

Hi Hoping for a little advice re aircon.

I have a 93 Jap import FD. My aircon worked when I bought it but 6 months later it had faded and no longer worked. I paid for a recharge and it worked fine for 2 weeks. After 2 weeks a white mist was vented into the car while I was driving along with the aircon on. Since then the aircon stopped working again.

Any idea what happened? Is anyone at fault?

Thanks in advance.

Phil

dgeesaman

iTrader: (7)

That happened in my buddy's car. He needed a new compressor I think.

Airconditioning is a dicey system to work on. On one hand, you ought to replace everything since they all have seals that could leak and let go, but on the other hand the point is to find the problem and fix it. If your current charge pressures are higher than before, it could have simply killed the next-weakest seal in the system.

Dave

DaveW

Dave G answered the main question, but the "white mist" was just condensation from cooling humid air, or from moisture left in the evaporator. In either case, this is common, and not related to the AC failure.

Philo

Thanks for your help.

Well I took it to AC bloke who recharged it recently.
I’m told that there is a switch that controls pressure. When the pressure gets too much it shuts off the pump. On my car the switch does not always shut of the pump. So what happened was pressure built up until it was too much and the Freon gas was pushed out the system through the air vents (aka the white mist). It still works and I could recharge it and use it in short bursts only but there is a risk the switch will just stick again. What I really need to do is replace this pressure switch, which I’m told is cheap parts wise but is a dash out job.

JM1FD

iTrader: (1)

Wow. So much misinformation....where to begin??

The high pressure cutout switch is under the hood, it screws onto one of the lines for the reciever/dryer. The switch under the dash is a thermoswitch to prevent the evaporator from freezing over.

I'm not sure if these cars have a high pressure relief valve (the thing that would vent off refrigerant), but if they do it is most likely located near or on the compressor....NOT in the dash.

Philo

Thanks, I am just trying to understand what i need to do to fix it. The fact that when it works it works well suggests to me a relativly cheap fix...
I accept the white mist could be unrelated, I am not even 100% sure if i had the aircon a day or 2 after that.

Still is the diagnosis of the pressure switch failing, pressure rising and blowing out the coolant a reasonable one?

Could it just be the aircon man is wrong about what switch is under the dash?

What do you guys think should be my next step? Take it to a different aircon shop and re-explain it all to them?

JM1FD

iTrader: (1)

First thing's first....it would seem that you have a refrigerant leak somewhere. DO NOT RUN THE SYSTEM UNTIL YOU KNOW IT IS PROPERLY CHARGED. You will RUIN the compressor by frequently running it with the charge low.

Get the leak fixed, and have them replace the receiver/dryer when they open the system up to fix the leak. A new receiver/dryer is cheap insurance against moisture related failures in the future. Since, as you say it works well when it works, I suspect you'll find that it will run fine once the leak is fixed and the proper amount of refrigerant is in the system.

If your radiator fans aren't running, or if you've got a bunch of CRAP in the condenser preventing proper airflow then the system might be shutting down on high head pressure....but considering you haven't mentioned overheating your engine, and you're in Jolly Ol' England where it doesn't really get SUPER hot outside, I would be inclined to believe that the high pressure cutoff switch is defective theory is, as y'all say, bollocks.

I would suggest that you find a new shop since it sounds like the one you've been dealing with doesn't know what they're doing. Find another shop.

Philo

Just to update this.

I did take it to a new aircon shop who completely contradicted the first shop.
- They could not find any dye from when the aircon was originally charged.
- When they charged it they immediately identified a slow leak in the condenser.

So now, hopefully all I need to do is find a condenser...