Air-conditioning not working

FrazzleTC · 18th April 2014, 13:48

Well, now the weather's hotting up, and the air-con should be making a noticeable difference, my 75's air-con is no longer cooling the car, as it should. There's actually no difference between the air-con being on, and in economy mode. I always run the car with the air-conditioning on, so it's not from lack of use.
The gas was recharged around a year ago, and it was fantastic all summer. However, now there's nothing. I can hear the pump kicking in and out when switching between economy and auto, and, my cooling fan definitely works.

Anyone got any ideas, as any help would be gratefully received.

SD1too · 18th April 2014, 15:32

Well Fraser, here are some ideas:

Check that the radiator fan is definitely starting when the compressor engages (proving it's the slow speed).
You hint that you haven't used the air con. much since last summer. You therefore might have lost a fair bit of refrigerant reducing efficiency greatly. Call out a mobile air con. engineer to check your pressures and charge.
Your system's drier might be saturated. This was diagnosed at my last 'service'. After 40 minutes of vacuum, and a recharge, cool air returned. As with your car, all hardware was working.
Your condenser may have deteriorated such that it is unable effectively to cool the refrigerant, even with the fan running.

Simon

MrDoodles · 18th April 2014, 15:35

Quote:

Originally Posted by SD1too

Your condenser may have deteriorated such that it is unable effectively to cool the refrigerant, even with the fan running.

Would be my 1st guess, but you really need to get it hooked up to a proper air-con machine to see if it'll pull a vacuum 1st, if it won't, then you have a leak!

Then you get get some UV dye put into the system with some Nitrogen in order to pinpoint where it is!

FrazzleTC · 18th April 2014, 21:43

I've definitely always been using the air-con when the car's been used.
The fan definitely works on low speed too.
How do I check the drier?
Could be a condenser problem too.

SD1too · 19th April 2014, 08:26

Quote:

Originally Posted by FrazzleTC

How do I check the drier?

It can't be checked. You have to call out an air con. agent to remove the stored moisture by evacuating the system and holding a vacuum for 40 minutes. This is what you should now do.

Simon

18th April 2014, 13:48	#1
FrazzleTC This is my second home Rover 75 Tourer Join Date: Sep 2011 Location: Staffordshire Moorlands Posts: 7,924 Thanks: 533 Thanked 1,178 Times in 920 Posts	Air-conditioning not working Well, now the weather's hotting up, and the air-con should be making a noticeable difference, my 75's air-con is no longer cooling the car, as it should. There's actually no difference between the air-con being on, and in economy mode. I always run the car with the air-conditioning on, so it's not from lack of use. The gas was recharged around a year ago, and it was fantastic all summer. However, now there's nothing. I can hear the pump kicking in and out when switching between economy and auto, and, my cooling fan definitely works. Anyone got any ideas, as any help would be gratefully received. __________________ 1967 Rover 2000 Automatic 1969 Rover 3500 Series One 1979 Scimitar GTE 2013 Mercedes SLK250 CDI

18th April 2014, 15:32	#2
SD1too Doesn't do things by halves Rover 75 2.5 Connoisseur Auto (1999) Dealer launch model. Join Date: Mar 2007 Location: Former Middlesex Posts: 20,590 Thanks: 1,587 Thanked 3,749 Times in 3,181 Posts	Well Fraser, here are some ideas: Check that the radiator fan is definitely starting when the compressor engages (proving it's the slow speed). You hint that you haven't used the air con. much since last summer. You therefore might have lost a fair bit of refrigerant reducing efficiency greatly. Call out a mobile air con. engineer to check your pressures and charge. Your system's drier might be saturated. This was diagnosed at my last 'service'. After 40 minutes of vacuum, and a recharge, cool air returned. As with your car, all hardware was working. Your condenser may have deteriorated such that it is unable effectively to cool the refrigerant, even with the fan running. Simon __________________ "Whatever is rightly done, however humble, is noble." Sir Henry Royce.

18th April 2014, 21:43	#4
FrazzleTC This is my second home Rover 75 Tourer Join Date: Sep 2011 Location: Staffordshire Moorlands Posts: 7,924 Thanks: 533 Thanked 1,178 Times in 920 Posts	I've definitely always been using the air-con when the car's been used. The fan definitely works on low speed too. How do I check the drier? Could be a condenser problem too. __________________ 1967 Rover 2000 Automatic 1969 Rover 3500 Series One 1979 Scimitar GTE 2013 Mercedes SLK250 CDI