Congratulations to vtecmec for winning May/June's Lude Of The Month, with his DIY Turbo BB1 build.

>>> Click Here For Profile <<<

Image

Air-con problem - Update on 'Auto' setting

Inside your car, there is an interior. Talk about it here
User avatar
simonc
Supporter 2016
Posts: 1609
Joined: Mon Mar 25, 2013 6:32 am
My Generation: 4G
Location: Halifax, W.Yorkshire, UK
Has thanked: 81 times
Been thanked: 53 times

Air-con problem - Update on 'Auto' setting

Post by simonc » Thu Jun 02, 2016 6:05 am

Hi all, got an interesting question about the air-con on my car. I apologise if this is a bit long winded but hope you’ll stick with me while I give you the full SP on this issue.

Here’s the problem, on a long drive (eg down to Singapore, approximately 4 hours each way, same kind of distance as Leeds to London), my air-con will give up the ghost about three quarters of the way, each leg of the trip.

After about three hours of driving (including a couple of stops for a fag and a coffee) I will begin to feel that the air-con starts to blow warm air through the vents. I don’t alter the temp, it’s always at 21 degrees and the fan is always at its lowest setting, but like I mentioned above, it just seems as though it’s decided enough is enough and it doesn’t want to blow any more cold air.

This of course, makes it murderously hot in the car and it becomes utterly miserable to drive.

I’ve noticed that the foam coating on coil under the passenger foot well is very wet to the touch and so what I’ve done, as my own kind of troubleshooting on these long drives, is to pull into a service station, shut the car down for a while and let things calm down.

After a ten minute break, I’ll set off again and the air-con will work quite well for a bit but seems to be struggling to cool the car, the air is definitely not ‘cold’ and after perhaps another thirty minutes or so, the air will be warm again so I’ll pull in and rest it for a while.

So there’s my problem guys, it’s this magical ‘three hour’ mark of pleasant cabin temperatures then an hour (actually more than an hour, as I have to keep stopping) of greenhouse temperatures making for a miserable drive in these temperatures. What’s happening?

More background, late last year we fitted a new cooling coil and a couple of months ago, we fitted a new compressor and alternator.

Here's the compressor
Image
The new old stock alternator
Image
The new cooling coil
Image

The problem is the just the same as it was before we fitted these new parts to the car. Every time I’ve been on a long drive, the air-con decides to blow hot air after approximately three hours or so.

Are there any air-con gurus that can shed light on this horrible problem and suggest a remedy or even a list of troubleshooting options Jason and I could work through in an effort to resolve it?

Again, I apologise for this being so long winded but if anyone could help, I’d be very, very grateful for your direction and assistance. Thanks for taking the time to read this, Si.

Forgot to add the obvious but just to let you know the gas pressure is as it should be.
Last edited by simonc on Fri Jun 03, 2016 11:08 am, edited 1 time in total.
'Mr Bridger, will drive them, into the sea...'

User avatar
bb1boy
Posts: 4459
Joined: Mon Jan 30, 2012 11:57 am
My Generation: 4G
XBOX GamerTag: adam fantastic

Post by bb1boy » Thu Jun 02, 2016 9:19 am

I have no real clue mate.. At a guess, I'd say if the gas is right, it must be the pump failing (over heating maybe) or the condenser is buggered and stops condensing (again, when it gets hot).. Because it starts OK and is OK again next time, something in the system is changing after 3 hours and then changing back. Could it be heat expansion and reduction of something? Ramble, ramble, sorry..
Image

User avatar
indigolemon
The Chaos Engine
Posts: 6676
Joined: Wed Jun 30, 2010 1:45 pm
My Generation: 4G
PSN GamerTag: M149YSL
Location: Kelty, Fife
Has thanked: 20 times
Been thanked: 70 times
Contact:

Post by indigolemon » Thu Jun 02, 2016 12:15 pm

Hi Simon,

As an experiment, try running the fan at a much higher setting and see if it lasts any longer. Low air flow speeds can actually cause parts of the system to ice up - preventing airflow, and therefore cooling. This would tally with it working again after being left for a while.

Graham
'On two occasions I have been asked, 'Pray, Mr. Babbage, if you put into the machine wrong figures, will the right answers come out?' I am not able rightly to apprehend the kind of confusion of ideas that could provoke such a question.' - Charles Babbage

3rd gen steve
Posts: 106
Joined: Sun Feb 05, 2012 10:14 am
My Generation: 3G

Post by 3rd gen steve » Thu Jun 02, 2016 1:20 pm

indigolemon wrote:Hi Simon,

As an experiment, try running the fan at a much higher setting and see if it lasts any longer. Low air flow speeds can actually cause parts of the system to ice up - preventing airflow, and therefore cooling. This would tally with it working again after being left for a while.

Graham
This could well be the cause of the problem. The fact that there is moisture on part of the system points to this as well. There should be a drain somewhere on the car to let the build up of ice melt away, usually on the bulkhead or on the floor near the the front of the car. If that is blocked in any way it could affect the efficiency of the system.

User avatar
Confused
Posts: 749
Joined: Fri Jan 27, 2012 11:44 am
My Generation: 4G
Location: Notts / Essex
Has thanked: 3 times
Been thanked: 11 times
Contact:

Post by Confused » Thu Jun 02, 2016 1:50 pm

As has been said, if set manually to a low fan speed, then the system will actually be working harder than if the system is left to full automatic.

There is a small rubber drain plug which comes out from the passenger bulkhead/footwell, and allows the evaporated water to escape. You should see a puddle of water under the car if the A/C has been running when parked. If this is blocked, then the water will either freeze up on the evaporator (what you have been calling the 'cooling coil'), or it will spill over into the car, and soak the carpet on the passenger side footwell (which can cause misting of the windows when parked, and there will of course be extra moisture in the air, which the A/C system needs to remove too!)

So - first off check that this drain is working properly. Secondly, try the fan on a higher speed (set it to Auto, and if you don't like it blowing on your face, point the vents away from you).

It could also be the receiver/dryer unit (which is located at the front of the car, behind the bumper, a cylindrical unit approx 3" in diameter and about 8" tall) failing.

User avatar
wurlycorner
Ye are glad to be dead, RIGHT?
Posts: 21195
Joined: Sat May 19, 2012 3:33 pm
My Generation: 4G
Location: Chelmsford, Essex
Has thanked: 1911 times
Been thanked: 235 times

Post by wurlycorner » Thu Jun 02, 2016 3:27 pm

Exactly my thoughts also - evaporator icing up.

User avatar
simonc
Supporter 2016
Posts: 1609
Joined: Mon Mar 25, 2013 6:32 am
My Generation: 4G
Location: Halifax, W.Yorkshire, UK
Has thanked: 81 times
Been thanked: 53 times

Post by simonc » Fri Jun 03, 2016 1:32 am

This is top rank stuff, gentlemen for which I thank you very much. There’s so much to go through so I’ll do it in a list form if that’s okay.

1: This drain thing could be a problem because I have noticed that very rarely do I get a puddle under my car. This is obvious because in every underground car park here, there’s always a puddle under each car when they’ve parked, mine however doesn’t seem to leave its signature puddle, so perhaps you’re onto something there.
2: I will definitely try the ‘Auto’ switch mode. To be honest, I’ve never used ‘Auto’ as I didn’t know what it did. On my way home tonight, I’ll switch it on, turn up the fan a bit and leave it on Auto for the rest of the weekend.
3: One time, actually when Linda was in the car with me, I noticed that water had dripped (quite a lot) onto the passenger foot well mat. It only happened once, quite a while ago and has never happened since.

Yesterday, I did meet with Jason as I needed to pay him for the work we did last Monday and I asked about the drain thing as I’d seen something about that on a website. He said it was okay and, I’m not casting aspersions, but as tomorrow we’re scheduled to fit the new air-con control box, I’ll ask to see for myself that this drain hole is not blocked.

Jason’s well aware of this issue with the air-con so as I said, tomorrow will be an air-con day where we can go through your points, one by one, to get to the bottom of it.

I am so very grateful for all your considered and thoughtful replies. Once again, you’ve helped me out tremendously and I thank you all very much indeed.

I’ll report back over the weekend, with pics, and let you know how we get on and in the meantime I’ll switch to ‘Auto’ and see if that makes any kind of difference. More from me soon, thanks fellas. ;)
'Mr Bridger, will drive them, into the sea...'

User avatar
hondaddict
Posts: 275
Joined: Sun Mar 06, 2016 2:51 pm
My Generation: 3G
Been thanked: 1 time

Re: Air-con problem - help please.

Post by hondaddict » Fri Jun 03, 2016 7:02 am

Hello Simon.

Unfortunatly, i couldn't help you but i just want to add that i use to have exactly the same problem with my first Prelude, a 4th gen BB3

I went to a specialist of automotive aircon, all the aircon system was tested. There was no gas leak and the system was fully working but was still "off" after a few hours...

So i never find where was the problem really, all the aircon sensors were fully working and the only thing i didn't test was the compressor control module.
Maybe a bad soldering is the answer to your problem, you should look at this module maybe and resolder it.

Hope it will help you and my apologize for my bad English :oops:
Accord Type R , "what else" :lol:

User avatar
simonc
Supporter 2016
Posts: 1609
Joined: Mon Mar 25, 2013 6:32 am
My Generation: 4G
Location: Halifax, W.Yorkshire, UK
Has thanked: 81 times
Been thanked: 53 times

Post by simonc » Fri Jun 03, 2016 11:07 am

@hondaddict, thank you for that information, I'll pass this on tomorrow. BTW, your English is perfect. ;)

Update

Been driving around today with the setting on 'Auto' which seems to make the fan run at full pelt all the time. Is it supposed to do that? With this full speed fan comes a ton of awful vibration under the bonnet. I mean, big time vibration. Is that an effect of the 'Auto' setting?
Sorry for the nagging but as I'm seeing Jason tomorrow, I'd love to go armed with as much info as possible. Thanks lads, Si.
'Mr Bridger, will drive them, into the sea...'

User avatar
bennyboy
Art Mechanic
Posts: 2825
Joined: Sat Aug 20, 2011 11:59 am
My Generation: 4G
PSN GamerTag: OCbennyboy
Location: St Albans, Herts.
Has thanked: 7 times
Been thanked: 21 times
Contact:

Post by bennyboy » Fri Jun 03, 2016 11:27 am

Trying to think about this logically, the pump is a switched auxiliary unit so it doesn't drain engine power all the time, it's just switched on when needed.
A think hondaddict may have a point - If you find after a while it stops working, I wonder if there's a solder joint somewhere that is opening up with the heat and stopping the pump kicking in, then closing, back to normal etc etc.. Bit like the fuel main relay issue.
Not sure where the relay is for the AC pump, but worth a look for sure as it'd be a simple fix.
UKDM BB1 H22A8 NH561P 244bhp 173lbft

'Nigella'

www.benaskem.co.uk

Post Reply

Return to “Interior”