no aircon but compressor running

Annie · 13th March 2017, 18:34

hi guys, first post.
went to use the air con today but doesnt blow cold and when you press the button you can see the compressor clutch engage and spin properly. so I was thinking it can't be low gas. I'm ok with spanners but know nothing of how AC works, any clues as what to test next. have cleaned out the plenum and changed filters etc aswell
annie

macafee2 · 13th March 2017, 19:41

I would take it to an air con place and have them test. When mine did this in 2016 or 2015 it was out of gas. I think the gas is harmful to the environment and so should not be allowed to escape, not that some scrap yards care.
I will be corrected if wrong.

macafee2

grivas · 13th March 2017, 20:13

Quote:

Originally Posted by Annie

hi guys, first post.
went to use the air con today but doesnt blow cold and when you press the button you can see the compressor clutch engage and spin properly. so I was thinking it can't be low gas. I'm ok with spanners but know nothing of how AC works, any clues as what to test next. have cleaned out the plenum and changed filters etc aswell
annie

Seek advice from an air con specialist, the entire system needs service, that means, evacuating, to remove all moisture, recovering what gas is left and topping up with new gas and the correct lubricant for the compressor. checking for leaks, as the seals dry-up with luck of use, also checking belts are healthy.
A word to the wise, DO NOT operate the system until it is serviced, or your compressor will die a most terminal death.

T-Cut · 13th March 2017, 21:07

As a DIY check, first ensure the slow speed works on the radiator fan. It's needed by the aircon system to cool the condenser. That's located in front of the engine radiator. The usual cause of poor aircon performance isn't lack of gas, it's loss of the slow speed cooling fan.

Running a diesel means engine cooling is rarely needed so the aircon performance is often the first sign that the fan has packed in. You can confirm this diagnosis by running the Demist test. This invokes aircon and the fan should start immediately at low speed (a relative term, it's actually quite fast). If the fan trips on after a few minutes and pulses on and off )at higher speed) then you need to fix the fan. Doing that depends on whether you have the older 3-speed or the later 2-speed system.

If you want to run this check and need more info, search for 'Demist Test' or come back here.

TC

Annie · 14th March 2017, 07:08

thanks for explanation.
The fan doesn't turn at all,
the handbook says the compressor won't run if low on gas , so the gas is ok so must be the fan or some sort of controller.

SD1too · 14th March 2017, 07:34

Quote:

Originally Posted by Annie

The fan doesn't turn at all,
the handbook says the compressor won't run if low on gas , so the gas is ok so must be the fan or some sort of controller.

Exactly Annie, T-Cut's advice is spot-on.

The next stage is to look to see if you have a 2 or 3 speed fan system. Here's how to do it.

Simon

Annie · 14th March 2017, 08:26

just had a quick look and can't see a resistor but very dark, may take off front bumper to be completely sure

Annie · 14th March 2017, 11:24

there is no resistor in place.

T-Cut · 14th March 2017, 11:44

Quote:

Originally Posted by Annie

there is no resistor in place.

For fixing the fan, you have a couple of options. Try a motor rebrush or replace the whole shebang with the later 2-speed/aftermarket alternative. It's all written up in the HowTo section.

TC

Annie · 14th March 2017, 11:58

great. thanks. will go and have a good read.

13th March 2017, 18:34	#1
Annie Avid contributor 2002 CDT Auto Con SE Saloon Join Date: Jan 2017 Location: Worthing Posts: 113 Thanks: 62 Thanked 15 Times in 14 Posts	no aircon but compressor running hi guys, first post. went to use the air con today but doesnt blow cold and when you press the button you can see the compressor clutch engage and spin properly. so I was thinking it can't be low gas. I'm ok with spanners but know nothing of how AC works, any clues as what to test next. have cleaned out the plenum and changed filters etc aswell annie

13th March 2017, 19:41	#2
macafee2 This is my second home Rover 75 Saloon & Tourer Join Date: Sep 2012 Location: Lincoln Posts: 14,931 Thanks: 1,630 Thanked 3,032 Times in 2,181 Posts	I would take it to an air con place and have them test. When mine did this in 2016 or 2015 it was out of gas. I think the gas is harmful to the environment and so should not be allowed to escape, not that some scrap yards care. I will be corrected if wrong. macafee2

13th March 2017, 21:07	#4
T-Cut This is my second home Rover75 and Mreg Corsa. Join Date: Nov 2006 Location: Sumweer onat mote o'dust (Sagin) Posts: 21,753 Thanks: 341 Thanked 3,660 Times in 2,924 Posts	As a DIY check, first ensure the slow speed works on the radiator fan. It's needed by the aircon system to cool the condenser. That's located in front of the engine radiator. The usual cause of poor aircon performance isn't lack of gas, it's loss of the slow speed cooling fan. Running a diesel means engine cooling is rarely needed so the aircon performance is often the first sign that the fan has packed in. You can confirm this diagnosis by running the Demist test. This invokes aircon and the fan should start immediately at low speed (a relative term, it's actually quite fast). If the fan trips on after a few minutes and pulses on and off )at higher speed) then you need to fix the fan. Doing that depends on whether you have the older 3-speed or the later 2-speed system. If you want to run this check and need more info, search for 'Demist Test' or come back here. TC

14th March 2017, 07:08	#5
Annie Avid contributor 2002 CDT Auto Con SE Saloon Join Date: Jan 2017 Location: Worthing Posts: 113 Thanks: 62 Thanked 15 Times in 14 Posts	thanks for explanation. The fan doesn't turn at all, the handbook says the compressor won't run if low on gas , so the gas is ok so must be the fan or some sort of controller.

14th March 2017, 08:26	#7
Annie Avid contributor 2002 CDT Auto Con SE Saloon Join Date: Jan 2017 Location: Worthing Posts: 113 Thanks: 62 Thanked 15 Times in 14 Posts	just had a quick look and can't see a resistor but very dark, may take off front bumper to be completely sure

14th March 2017, 11:24	#8
Annie Avid contributor 2002 CDT Auto Con SE Saloon Join Date: Jan 2017 Location: Worthing Posts: 113 Thanks: 62 Thanked 15 Times in 14 Posts	there is no resistor in place.

14th March 2017, 11:58	#10
Annie Avid contributor 2002 CDT Auto Con SE Saloon Join Date: Jan 2017 Location: Worthing Posts: 113 Thanks: 62 Thanked 15 Times in 14 Posts	great. thanks. will go and have a good read.