Pixelfill Posted June 18, 2010 Share Posted June 18, 2010 Apologies for the long post in advance. Right I've got a problem with my A/C, when I switch it on the light above the AC illuminates, but the air coming through the vents is no cooler than ambient. I bought a regas kit from Halfords, and tried to repressure the system. At an ambient temp of 21degrees the can said to fill between 30 and 45 psi. as I got to about 40psi the pressure dropped to zero (This was either the compressor kicking in, or stopping and I realise now I then made the mistake of trying to increase the pressure) I've done the diagnostic test and just got the solar sensor warning (Front Demister) With the engine idling for a while, and on a short drive, I didn't notice the compressor kicking in. However I have checked the magnetic clutch relay and that is fine. I bridged the connection to override the relay and the compressor kicks in fine (still no cold air though) Whilst fiddling with the bridged connection I checked the sight glass and there are no bubbles, when disabling the compressor the sight glass "foams" and then clears. I checked the pressure again, and I think it's possibly a touch high 50psi at about 20degrees. Any ideas as to why my A/C isn't cold, and yes the temp control is set to low. Thanks Mike Quote Link to comment Share on other sites More sharing options...
stevie_b Posted June 18, 2010 Share Posted June 18, 2010 I would take it to a garage or an aircon specialist. They can use UV dye in the refrigerant to see if there are any leaks anywhere. Quote Link to comment Share on other sites More sharing options...
dude Posted June 19, 2010 Share Posted June 19, 2010 Apologies for the long post in advance. Right I've got a problem with my A/C, when I switch it on the light above the AC illuminates, but the air coming through the vents is no cooler than ambient. I bought a regas kit from Halfords, and tried to repressure the system. At an ambient temp of 21degrees the can said to fill between 30 and 45 psi. as I got to about 40psi the pressure dropped to zero (This was either the compressor kicking in, or stopping and I realise now I then made the mistake of trying to increase the pressure) I've done the diagnostic test and just got the solar sensor warning (Front Demister) With the engine idling for a while, and on a short drive, I didn't notice the compressor kicking in. However I have checked the magnetic clutch relay and that is fine. I bridged the connection to override the relay and the compressor kicks in fine (still no cold air though) Whilst fiddling with the bridged connection I checked the sight glass and there are no bubbles, when disabling the compressor the sight glass "foams" and then clears. I checked the pressure again, and I think it's possibly a touch high 50psi at about 20degrees. Any ideas as to why my A/C isn't cold, and yes the temp control is set to low. Thanks Mike For little more than you paid for that kit Kwik fit would have charged the system for you. Quote Link to comment Share on other sites More sharing options...
cashpoint Posted June 19, 2010 Share Posted June 19, 2010 For little more than you paid for that kit Kwik fit would have charged the system for you. My local kwik fit shanged mine but as my aircon still didn't work(aftermarket ECU seems to be causing some problems) they didn't even charge me. Quote Link to comment Share on other sites More sharing options...
Pixelfill Posted June 19, 2010 Author Share Posted June 19, 2010 For little more than you paid for that kit Kwik fit would have charged the system for you. yeah I know - but would they have been able to diagnose the problem now ? Mike Quote Link to comment Share on other sites More sharing options...
richarde7927 Posted June 19, 2010 Share Posted June 19, 2010 I work for a accident repair centre and do air con stuff . you need to get it put on a good mechine , just because you have pressure in there does not mean its air con gas , there could be loads of air in there ,they would start by recover the system and then vacuuming it for 30 mins ,then see if the system holds a vacuum , if so it does, regas the system with the right weight in gas and job done . If the system does not hold a vacuum , put some dye in the system and some gas and then use a ultraviolet light to find the leak . Rich. Quote Link to comment Share on other sites More sharing options...
Pixelfill Posted June 19, 2010 Author Share Posted June 19, 2010 good point On a plus side it does seem to be holding pressure Would the car prevent the compressor from activating if the pressure was too high ? I'm just trying to work out why the A/C doesn't seem to be activating the magnetic clutch Mike Quote Link to comment Share on other sites More sharing options...
richarde7927 Posted June 19, 2010 Share Posted June 19, 2010 There are sensors around the system that measure pressure and temp to control the pump and fan to cut them in and out by the ecu as needed . if the system see's anything outside the box's so to speak the air con pump will not cut in to save the system from damage . Rich. Quote Link to comment Share on other sites More sharing options...
Pixelfill Posted June 19, 2010 Author Share Posted June 19, 2010 Right - quick update - it seems that the clutch is engaging, but I'm just not getting any cold air - I'm going to take it to a specialists (not Kwik fit ) and see what they can make of it - I'm hoping a regas will sort it out. Mike Quote Link to comment Share on other sites More sharing options...
Kirk Posted June 19, 2010 Share Posted June 19, 2010 It sounds like just a regas job to me mike but ive been wrong before Having had a load of recharges to do over the last few weeks it does sound like the gas is either not present or just old. Saying that though the dryer might be getting tired Quote Link to comment Share on other sites More sharing options...
Ibrar Jabbar Posted June 19, 2010 Share Posted June 19, 2010 Right - quick update - it seems that the clutch is engaging, but I'm just not getting any cold air - I'm going to take it to a specialists (not Kwik fit ) and see what they can make of it - I'm hoping a regas will sort it out. Mike If the pressure on the low side is dropping to zero whilst the compressor is running, then it sounds like a faulty expansion valve pulling the low side into a vacuum. Quote Link to comment Share on other sites More sharing options...
Pixelfill Posted June 19, 2010 Author Share Posted June 19, 2010 If the pressure on the low side is dropping to zero whilst the compressor is running, then it sounds like a faulty expansion valve pulling the low side into a vacuum. Oh that doesn't sound good - in fact it sounds expensive Mike Quote Link to comment Share on other sites More sharing options...
Ibrar Jabbar Posted June 19, 2010 Share Posted June 19, 2010 It won't be cheaper than a regas I'm afraid. If it is the expansion valve, it will need replacing along with the drier / receiver and the system flushed and re gassed. Quote Link to comment Share on other sites More sharing options...
Pixelfill Posted June 19, 2010 Author Share Posted June 19, 2010 will a regular air con specialist be able to diagnose / rectify this or would I be better taking it to a Supra guy? Mike Quote Link to comment Share on other sites More sharing options...
Pixelfill Posted June 19, 2010 Author Share Posted June 19, 2010 (edited) I think I've just answered my own question - please tell me the expansion valve isn't behind the dash is it? Are we talking a big job here? I have a sneaking suspicion that this awaits me ... http://www.mkivsupra.net/vbb/showthread.php?p=2737229&postcount=18 Edited June 19, 2010 by Pixelfill (see edit history) Quote Link to comment Share on other sites More sharing options...
Ibrar Jabbar Posted June 19, 2010 Share Posted June 19, 2010 An experienced air con specialist should be able to diagnose the fault fairly easily so you are better off taking it there. If it is the expansion valve it can be accessed by removing the glove box and the evaporator, i.e the complete dash does not need to be removed to get to it. Quote Link to comment Share on other sites More sharing options...
Pixelfill Posted June 19, 2010 Author Share Posted June 19, 2010 oh thanks Ibrar, I was starting to worry - quite a lot I'll get someone to have a look for me. Quote Link to comment Share on other sites More sharing options...
Pixelfill Posted June 27, 2010 Author Share Posted June 27, 2010 Well just to follow up on this tale. I had the system regassed and fingers crossed it all seems to be working correctly. Although the system had about the correct pressure it didn't have enough refrigerant. Mike Quote Link to comment Share on other sites More sharing options...
richarde7927 Posted June 27, 2010 Share Posted June 27, 2010 Well just to follow up on this tale. I had the system regassed and fingers crossed it all seems to be working correctly. Although the system had about the correct pressure it didn't have enough refrigerant. Mike So i was about right in the first place then , although there is pressure it does not mean it air con gas , do you use your air con in the winter . with the heaters , its best to use it when you can as the system has oil in it and by using it it moves the oil around and stops the seals from drying out a leaking out the gas , plus it as de mists the windows loads faster than the heaters on there own . Rich. Quote Link to comment Share on other sites More sharing options...
Pixelfill Posted June 27, 2010 Author Share Posted June 27, 2010 So i was about right in the first place then , although there is pressure it does not mean it air con gas , do you use your air con in the winter . with the heaters , its best to use it when you can as the system has oil in it and by using it it moves the oil around and stops the seals from drying out a leaking out the gas , plus it as de mists the windows loads faster than the heaters on there own . Rich. I don't use the car as much as I should - and use the air con less, but yeah seems you were pretty spot on. I'm confused about how the refrigerant could be replaced, but happy to have solved the problem without needing to delve behind the dash Quote Link to comment Share on other sites More sharing options...
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