Air Con re-gassing / lack of compressor activity

[WRDendy]

I'm trying to resurrect my air-con - it worked most of the time last summer, but is doing absolutely nothing now. It's an R134a system so fortunately gas is readily available.

The symptoms are a complete lack of activity when I press any of the air con buttons on the VEM. If it was working normally, I'd expect to hear a relay click followed by the car revving slightly higher and the voltmeter going down slightly as the compressor kicks in.

I suspect that the system pressure may be low as it wasn't 100% reliable last year, but I can't check it as connecting a gauge to the low pressure port gives me a meaninglessly high reading. From previous research, I believe that the port being on the accumulator itself means that I'll only get an accurate reading (and can only pump in new gas) when the system is running, and furthermore the system will only run when pressure is over a certain threshold to prevent damage, so you can probably see the catch 22 that I find myself in.

I've identified what I believe to be the AC relay in the relay box under the bonnet, which I will test on the bench tomorrow. Does anyone know if there are any other relays in the VEM or anywhere else that are involved in activating the compressor? In either case, would I be ill-advised to manually make a connection across the socket in the relay box to see if I can get the compressor running for long enough to take a reading and feed some gas in?

[brinkie]

Don't mess with it yourself and take your car to an aircon specialist. Even the fastfitters can do the job, I have seen prices as cheap as 48 pounds for a/c service. What they do is connect your car to specialized equipment, that will first drain your system, measure the amount of R134a gas that is in there and compare that with the amount that should have been in there. If only a small amount was missing, there may be another problem in your a/c system, but 99 out of 100 cases it is just the coolant gas that has gone missing! Then they will refill the system with the proper amount of R134a and some special oil for lubricating the a/c pump. This is a fully automated process and I have service my 480 twice at two different places, both had no problem at all connecting the car to the equipment. It has set me back 70 Euros.

Sadly, the system in my car has sprung a leak in the condensor, and the condensor has become unobtainium. Although several suppliers claim they have them in stock, it is in fact that they order them at Hella, who has gone out of stock several years ago, but no one seemed to care for an update of the web site.

[WRDendy]

You won't believe what just happened - I went outside and turned the car on just to see what would happen (it hasn't worked all year - why not try it once more?) and the compressor kicked in straight away!

Sure enough, low-ish pressure in the system according to the gauge so probably just not enough for it to work, and my cylinder of R134a is nearly empty so nothing doing there either

I shall act accordingly and probably take it to the local kwik-fit or similar. I have no qualms about re-gassing my daily car myself, but for obvious reasons I'd rather not blow up the 480 over a matter of £50 or whatever it costs.

Sometimes I sympathise with Basil...

[brinkie]

I surely do sometimes
https://www.youtube.com/watch?v=78b67l_yxUc

[dcwalker]

Sometimes I sympathise with Basil...

Typical 480 - unpredictable!

Did you threaten it with the Basil treatment before trying the AC again today Will? They do listen sometimes you know...

Be interested to hear if a recharge works as I have to think about that for Lily too.

David

[dragonflyjewels]

Al's ac is dead as well - currently in the garage having a secondhand evaporator fitted as ours was leaking. Hope this one's good, otherwise we'll be raiding the GT we bought for spares.
In dire circumstances, try the threat of the scrapyard. Surprising how many of my garden plants have responded to the threat of the compost bin......

[jifflemon]

I shall act accordingly and probably take it to the local kwik-fit or similar. I have no qualms about re-gassing my daily car myself, but for obvious reasons I'd rather not blow up the 480 over a matter of £50 or whatever it costs.

Avoid Kwik-fit. You want a PROPER specialist, not monkeys with all the gear and no idea.

I use these guys for my other cars (they'll be doing the 480 soon hopefully!)