Help,I am the very proud owner of 5 weeks of a F reg Royal Lounge.I phoned a company to come round and fill the air condishtioning unit with gas but for some reason the clutch will not turn.The light on the dashboard switch is on.There is no live going down to the compressure.Have checked fuses,their OK,Would like to know where the relay is and also the low pressure switch.any thing else you can think of would be a great help.Many thanks Lisa

- (#3693) Lisa, 7 Jul 02

Lisa,
you don't say if you actually have had the air con emptied & refilled or not. Unless you have a post '95 model then you would have had to have had the R12 gas (now illegal) removed (if there was any left) and the receiver dryer renewed, the system pressure tested for leaks & finally refilled with R134a gas, with the correct amount of PAO68 or PAG oil. If this wasn't done, or you have a leak, then you most likely haven't got any gas in the system, no gas = no pressure, no pressure kicks in the pressure switch so that the system will not operate so as to prevent the compressor overheating & self destructing. If you did have the system refilled, then I suggest you get the fitter back, because at best he hasn't got your system working, at worst he hasn't done the 'retro fit' procedure listed above, and therefore the system can't possibly work. If he has put R12 in the system, he has commited an offence, if he has just refilled with R134a, then he has done a very bad practice, because you should always replace the receiver dryer & the oil when 'retro fitting'. BTW how much did he charge you. HTH regards Rob.

- (#3694) Rob Drinkwater, 7 Jul 02

Rob, it's still legal to top-up...

As previously mentioned, no, or insufficient gas will result in the compressor not pulling in. All the control gear is behind the glovebox. Is it front& rear, and is there a fridge? Also, are the controls manual, or is it an auto aircon (climate control) version?

- (#3698) david miller, 8 Jul 02

Rob & David thank you for your reply. The fitter topped up the air con with enough gas he said to get the compresser working and to do a leak check,compresser did not work but electric fan in front of rad did work.He put a test on the lead to the compresser there was no live so he put a live down to see if the compresser was working and it did.He said he thought that there might be a slight leak but that it was so small he didnt think that would stop it from working.He thinks its an electrical fault.it has got climate control but we have tried it on all settings,it has got a fridge and air con in the back.we wondered if it could be a relay but are not sure which one it is.There are two relays on the drivers side of the fridge,One clicks when you engage the rear aircon on the dash board switch,but the second one does'nt click at all.The little man was very nice he stayed for about 4 hours to try to get it working and only charged me £20,and offered to help if we could find out anymore about the vehicle.Any further thoughts chaps.Lisa

- (#3710) Lisa, 8 Jul 02

One (of many) things that may be keeping the compressor off is, I believe, the system which cuts it out when you press the pedal to demand a lot of acceleration. This might have been disturbed when work was done - on the fuel pump? I don't know much about it. Can anyone explain?

- (#3721) Dave Mason, 9 Jul 02

Good point, Dave. A resistive throttle position sensor cuts the aircon under heavy acceleration. Don't know whether the TPS goes directly to the a/c amp or via the emmissions computer ECU. it is possible to misadjust it, or put it on incorrectly. If in doubt, remove the two screws and lift it off- it's a spring-return unit, si it'ss default to closed when removed...

- (#3724) david miller, 9 Jul 02

Good thinking, it had a new pump put on just before i brought,it then had to go back because it was not running right and thay said that they hadn't ajusted the pump properly.We will give it a go.Ill tell you how we get on.Many thanks.Lisa

- (#3727) lisa, 9 Jul 02

David, sorry got to contradict you on the law here, R12 is a CFC gas, completely BANNED from use in all EC countries from 1/1/01, this means that you cant use it for refilling, or topping up as you call it. It was banned from 1995 for fitment in new cars, but was allowed for refilling up until 1/1/01. Now only HFC gasses can be used such as R134a. Anyway, how can you possibly 'top up' you don't know how much gas is in the system, there isn't a dip stick, except maybe the 'air con expert' who tells you that you can 'top up', there is only one way to refill air con systems, that is to remove the gas, put the system into a deep vacuum, to boil off any moisture in the system, then to refill with the correct WEIGHT of gas, not to a pressure, as pressure is temperature dependant, weight is weight irrespective of temperature.

- (#3729) Rob Drinkwater, 9 Jul 02

yes Rob, you evacuate, then fill by mass. Low and high side pressures can be used then to verify correct functioning of the system, and may allow fine- tuning of the fill for best response. I believe the legislation you mention refers ONLY to the production and sale of NEW R12 product. As you are aware, CFC gases are a problem because they do not naturally degrade in the atmosphere, instead forming a shielding blanket at high levels and depleting ozone at the same time.
Check out Haynes 3740 aircon techbook if you have a copy.
So to stabilise the amount globally, no more is produced, however recovered R12 can still be used to keep older systems running. The reason conversion to R134a is recommended is because the newer gas is cheaper and easier to purchase...

- (#3735) david miller, 10 Jul 02

R12, must now be collected, stored in a 'scrap' cylinder clearly marked 'scrap gas' and must not be re-used (of course there are plenty that are flouting the law) it must then be collected by an approved agent such as BOC or Air Products to be destroyed (this involves burning it at very high temperatures in controlled conditions. You are quite correct that this CFC gas caused the ozone depletion, but the flip side of the coin is that R134a is an HFC gas (hydroflurocarbon) this adds to the greenhouse effect that stops the suns heat getting back out of our atmosphere, so the choice is CFC where we all burn, of HFC where we all overheat ???????. you are correct that that the gauges can then be used for diagnosis for problems or checking for over pressure situations, such as if a control valve is stuck closed etc. If you put the correct weight of gas back in the system in the first place then a 'top up' shouldn't be necessary. Regards Rob.

- (#3742) Rob Drinkwater, 10 Jul 02

Perfect world, Rob. But R12, and even worse with R132a, the molecules of gas will diffuse through the rubber of the "O" rings, seals, and flexible hoses. The refrigeration trade reckons on a 25- 100g loss per year in a good system. So eg, my system was evacuated last year, and 580g recovered, a loss of 620g in ten years.

- (#3743) david miller, 10 Jul 02

OK Rob, explanation accepted with apologies- I wasn't aware of the 01.01.01 change.
Strange isn't it, that it's better to destroy R12 than recycle. Ah well, c'est la vie, someone has to make money somewhere, and I'm told it's DuPont...
Pity too that so many aircon men are breaking the law. Maybe the law's an ass? Or maybe my aircon man, one of only two or three in N.I...Why did he top up for £50, when he could've converted to 134a for £250 and higher profitability!

- (#3744) david miller, 10 Jul 02

Absolutely right David, we have always reckoned to lose 10-15% per year out of a fully loaded system, losses reduce over the years to a point where only small amounts are lost due to lower pressure in the system. The more modern systems with neoprene seals (as opposed to rubber seals) tend to leak less, but 5% volume loss per year is accepted as the norm. Yes it does seem criminal to destry the R12 rather than recycle, but I suppose they would rather that all the 5-10% per year loss was R134a rather than R12. Alot of Air Con guys aren't set up to deal with 'retro fitting' as they don't have the equipment to recover the R12, change the receiver dryer, remove as much of the oil as poss, change all the seals if rubber (most vehicles after '91 up to the '95 change to R134a had neoprene seals, so these needn't be changed unless leaking) then fit adaptors to fit the R134a charge ports & then vac down, refill with correct weight of R134a, then completely refill with correct quantity of PAG (poly alkaline glycol) oil. (Have you ever tried to get the receiver dryer off a Townie, talk about Toyota making sure the thing will never fall of, the bracket could hold up the Eiffel Tower, if your guy knew this, he wouldn't want to get the RD off) Incidentally the R134a has a larger molecular structure than R12, so effectively takes up more volume for the same weight, so therefore you have to put 10-20% less weight in, to take up the same volume in the air con system. EG, 1400grams of R12, means you should refill with 1120-1260 grams of R134a. There are also some so called 'drop in gasses' around that are blends of other gasses (Including butane, would you want butane flammable gas in you system) floating around that are claimed to get around the 'rubber seal' problem, but they are less effective than either R134a or R12. Also the cooling effect of R134a isn't as good as R12 systems used to be anyway. There is also a supposedly universal system oil called PAO68, that is supposed to overcome the problem if you can't get all the oil out, I didn't fancy trying to get all the oil out of my compressor (would you like to take one off if you didn;t have to) so I removed what I could via the pipework, but had to leave what was in the sump of the compressor, I then refilled with a full quantity (8 FlOz) of PAO68 which just floats over the old oil & is carried by the R134a correctly to lubricate the whole system. It all works really well now I have converted over to R134a. Regards Rob. P.S. did you know that Townies with Dual systems also have a high side port behind the driver's seat, as you say, this can be used for diagnostics to see if both circuits are working correctly, or if you have one circuit with a faulty control valve.

- (#3746) Rob Drinkwater, 10 Jul 02

I was quoted for replacement with R24. A lot more expensive than R134a but better for the system.
No one has mentioned R24 does it exist or was my a/c man trying it on? He did say in his defence not to call him until the a/c does not appear to be working correctly, i.e. don't fix what is not broke, or was he booked up now the summer is here?

- (#3757) clive, 11 Jul 02

R24 is a commercial refrigerant used in such applications as lorry refridgeration unit, the ones that sit above the driver on artics. Not advisable on a car air con system as the molecular structure dictates that the system needs to be bigger for use with it. If you are really struggling, get him to use a 'blend' or 'drop in' gas to refill, without the need for 'retro fitting' to R134a, but really the best bet is to spend the money, bite the bullet & go over to R134a, then next time anyone can do the job at a reasonable cost. Regards Rob.

- (#3766) Rob Drinkwater, 11 Jul 02

I read my doodled note last night and it is RS-24 used in USA as a direct replacement for R12, ok with rubber seals in older systems ie. pre neoprene types. Don't know if it's the same as R 24, nor if our systems have rubber seals?

- (#3768) clive, 12 Jul 02

Clive, I think that it is basically a drop in gas, that is a 'get out of jail free' card, in other words it isn't a solution, it is merely a way of getting the air con gassed up for now, I understand that some of the drop in gasses can evaporate quite quickly, partly due to containing butane as on of the gasses in the blend. As regards the seals, sice you will need to remove the receiver dryer what ever you do, to replace it, you will have the opportunity to see the seals on the system, if they are black & rubbery looking, then they probably are rubber, if they are green or orange and slightly smoother looking, then they are probably neoprene and suitable for use with R134a. HTH Rob.

- (#3778) Rob Drinkwater, 12 Jul 02