Air con not working!

Thanks for that. I haven't tried any wacky additives and don't intend to, especially now after your advice!

So far all I've done is add around half the contents of a 12oz can, about 150 grams. It raised the pressure enough for the pressure switch to close and allow the compressor to start, but there was virtually no cooling.

When I came to add the rest of the can contents it must have seeped out of the charging hose when I left the can upstairs for a few hours cos the rest of the can was empty. Needless to say, I'm just awaiting delivery of a pack of 3 full 12oz cans.

I guess I've hardly added any refrigerant so far, so will add more when it arrives. It does seem to be holding the pressure as the compressor still starts ok after several days of no use.

I don't use it right now as a) it doesn't cool anyway, and b) I don;t want to cause damage running the system with low re-frigerant levels etc.

I can only use it when the car is moving at a reasonable speed anyway because the air-con main fan motor is seized solid and totally buggered-water got in and rusted the inside, causing one of the permanent magnets to bubble up with the rust and lock the motor armature solid.

I've just got hold of one on ebay for a whole lot less than a new one, and am just awaiting delivery. I understand the ssystem can overheat and pressures rise if the vehicle is stationary with the air-con on, and there is no cooling airflow through the condenser. I'll be using it only on the motorway until I get the fan sorted.

I don't know if the system was completely empty anyway, so all I can do for starters is to top it up myself before going to a garage and damaging the wallet!

I did notice an oily patch on the metal cooling fins of the main engine cooling system radiator and, as this sits right behind the condenser, I'm now wondering if there's a leak there. I imagine years of motorway cruising will have thrown stones at high speed right into the condenser matrix and holed it somewhere

I haven't had the car long, and have been doing a crash course on air-con in the last few weeks!

I can't tell whether the system was completely empty, but adding 150 grams did allow the compressor to start up, so there must have been some re-frigerant in there already.

I don't know if there's any air in the system and, if there was, how exactly do you remove it and charge the system into a vacuum?

My plan was to re-charge it myself and see if it holds pressure and works, as this is the most cost-effective start point. If it still leaked or didn't work, then the plan was to take it to an air-con specialist and work some overtime!

Thanks for your advice anyway, it was very useful as I never thought about air in the system

One more thing-I was told that when charging the system you look at the sight glass to see if there are any bubbles in the re-frigerant. I was told the sight glass was near where the hoses go into the bulkhead, but I can't seem to find any sight glass anywhere.

I've tried imagining I'm a molecule of re-frigerant (!), and following the progress from the compressor out into the condensor, then from the condensor into the receiver drier (thought the sight glass would be there like it was on old Ford Granada's etc), then folowed the pipe into the bulkhead. No sign of a sight glass anywhere!! Does it actually exist on this system or is it charged to a system pressure instead?

Alex

Thanks for all the detailed advice everyone Well, the story so far. I found the label under the bonnet-the system takes 1553 grams of R134a refrigerant.

The other small 340 gram cans arrived today, so I set about putting more R134a into the system. When all this milarky first started the compressor wouldn't even engage when selecting air-con when I tried it a little while back, as the system pressure was so low.

I put about 200 grams of R134a into the system last weekend and this time the compressor started but cooling was virtually non-existent, so I ordered more R134a, which arrived today.

Well, I started the engine with the whole air-con system cold, and started adding more R134a. After a little while the system warmed up and pressure in the charging pipe equalled pressure in the can, so the R134a stopped flowing.

What had happened was that the condenser was not being cooled, as the fan was seized solid and I'm still awaiting delivery of the replacement motor from an ebay seller, although I had completely removed the old fan and bracket.

When the whole system was stone cold this wasn't a problem, but after a short while the condenser warmed up and pressure built up in the charging line, stopping the R134a from flowing.

As I couldn't very well charge the system by driving fast to flow air over the condenser, I hit upon a novel way of cooling the condenser whilst the vehicle was stationary, and cleaning it of 10 years worth of dead flies and debris into the bargain.

I got the garden hose out and, with the jet nozzle attached, selected a slightly wide cold water spray pattern and proceeded to direct the spray pattern through the front kidney grilles and onto the condenser, and swept the water spray over the whole surface of the condenser.

Well, it worked!! R134a started flowing again and the system sprang into life-after a few more seconds operation ice-cold air was now being blown into the passenger compartment

I put in a full 340g can, so I have added myself around 500 grams to a depleted 1550 gram system, and it's now working fine. So the system wasn't empty thankfully, and seems to have lost around 1 third of it's capacity in 10 years, so it's not leaking, just weeping or seeping very slightly thankfully.

Anyway, it's holding pressure ok and I now use it only when moving at a reasonable forward speed until I get the new motor and fit it-hopefully this weekend. So a result! Thanks for all the advice guys-I'm ready to submit my Thesis on refrigeration now-ice cold drinks all round now I think

Alex (drives the coolest estate in town now-literally)

Yeah it was still a pig to get out cos I'm tall and lanky and contorting myself in the footwell was not the greatest way to spend a spare hour

I know it's easier on Left-hand drive cars, but I found that Right-hand drive cars with auto gearboxes have the advantage of no clutch pedal to get in the way. Maybe those horror stories were from Right-hand drive cars with manual gearboxes.

Well, the air-con is fully functional now. I re-fitted the fan at the weekend and re-charged the system fully. It now blows ice-cold and the fan works properly-all set for the long hot summer I'm sure we won't get

Alex