Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: NaughtyNigel on 08 June 2007, 12:17:18

Title: Omega Air Conditioning Problem Fixed
Post by: NaughtyNigel on 08 June 2007, 12:17:18
I have a 2001 model V6 AUto CDX which I have owned since new, and have loved almost every mile!

However, one problem that I suffered almost since new was that the windows tended to steam up very easily, and were almost impossible to clear using the climate control system. Even a heavy shower in the summer resulted in the windscreen misting up, simply becuase it cooled down the glass.

The only solution I ever found was to open the sunroof or windows to clear the exess humidity, although the problem returned as soon as the sunroof was closed again. At one stage I suspected that water was getting in somewhere, but I disproved that theory.

I know of other people who have suffered simialr problems in other Vauxhalls including Astras and Vectras, alhough my brother-in-laws Omega was never a problem.

Anyhow, after six years the original battery failed, so I fitted a new one myself. As if by magic the aircon problem dissapered, the car smells much fresher, and the aircon itself seems to work much better. As far as I can work out, this was the first time the battery had ever been disconncted, as I have never had to enter the radio code before, and our dealer doesn't know what the code is.

From what I can work out, the climate control system is electronically controlled, and uses firmware to manage the system. I suspect this had somehow become corrupted, therefore disconnecting the battery forced it to reboot.

It seems the system was recycling air regadless of the user settings, and could not be resolved even by pressing the Auto and Off buttons together as reccomneded in the manual.  

I hope this helps other readers. And if not, at least it doesen't cost anything to disconnect the battery for five minutes!
Title: Re: Omega Air Conditioning Problem Fixed
Post by: Marks DTM Calib on 08 June 2007, 12:29:01
There is a reset procedure that you can follow on the climate which rests the servo positions, it may well be this was all that was needed and occured automaticaly when the battery was changed

Other items to watch are:

1) Pollen filter, when blocked up it causes misting (more common on smaller cars becasue people just dont bother changing them!).

2) Scuttle drain, if blocked you can get water coming in through the heater system

3) Rear vents, the car has a set of vents in the boot (in the drivers side rear cubby hole on the saloon and behind the spare wheel on the estate) which allow air to pass through the car......dont block these off when stowing items for storage.

4) On the facelift Omega (late 1999 onwards), make sure you fit a carbon pollen filter (some try to save a few guid by fitting the older non-carbon version) as there is a polution sensor that turns on the re-circ if certain nasties are detected in the in-coming air, if its not carbon its more likely to enable the re-circ


Thanks for the feedback and I hope the above is of some use also.
Title: Re: Omega Air Conditioning Problem Fixed
Post by: NaughtyNigel on 29 June 2007, 16:07:26
Thanks for the comments Mark.

I did try the reset proceedure a few times, but it did nothing. And the main dealer has never been able to find anything wrong with it either.

I now have a new problem with the A/C, where the A/C fan switches off for no reason. Sometimes it comes back on after a few seconds, other times it will not work for some time. This again seems to respond to disconnecting the battery, or (I have found), pulling the relevant fuse from the box beside the battery.

I has all the hallmarks of a loose connection, but I suspect it is more likely to be yet another ECU fault (probaly in the fan speed controller). Otherwise, why would disconnecting and reconnecting the power make it work again? This has been going on now for about two years, but at least I know how to fix it now.

For reference it is a 2001 (facelift) 2.5 CDX Auto model.

Thanks again.

Nigel.
Title: Re: Omega Air Conditioning Problem Fixed
Post by: Mike Collins on 29 June 2007, 18:03:10
Does the compressor declutch when the fan stops? It may simply be low refrigerant level, has it ever had a check?
Title: Re: Omega Air Conditioning Problem Fixed
Post by: NaughtyNigel on 29 June 2007, 18:32:50
No: This is the blower fan in the climate control system, not the fan on the A/C condenser.
Title: Re: Omega Air Conditioning Problem Fixed
Post by: Mike Collins on 29 June 2007, 18:40:38
Probably worth looking at the fan speed controller, it's mounted on the fan body above and in front of the glove box. Has the left side scuttle drain been blocked and allowed water into the fan?
Title: Re: Omega Air Conditioning Problem Fixed
Post by: Matchless on 29 June 2007, 21:49:16
Bit of a fiddle to get the fan speed controller out (remove glove box and it is the square base clipped into fan casing with 4 or 6 wires) Once out you will see a long narrow cover which hides some soldered connections, prise this off and peep inside. If there is signs of water damage, ie furry corrosion or green stuff then this is likely to be your problem.

If you are OK with a soldering iron you can unsolder the wires and prise off the base. Then clean the circuit board throughly with IPA (isopropyl alcohol) and reassemble using a little non-acetic silicone sealant. This has worked a couple of times for me.
Title: Re: Omega Air Conditioning Problem Fixed
Post by: Mike Collins on 30 June 2007, 09:11:08
I'm glad someone else has taken one these apart, I found poor soldering of mosfet bodies to the heat sink, they overheat and short. Suitable replacements available from RS, but awkward to get good thermal contact. Still cheaper than new part.
Title: Re: Omega Air Conditioning Problem Fixed
Post by: Wayne on 14 September 2007, 22:10:13
whats the RESET Procedure for Air-Con on an Omega CDX 1998 S Registration ?

thanks very much
Title: Re: Omega Air Conditioning Problem Fixed
Post by: TheBoy on 14 September 2007, 22:14:58
Quote
whats the RESET Procedure for Air-Con on an Omega CDX 1998 S Registration ?

thanks very much
Press and hold auto and off for 5s...
Title: Re: Omega Air Conditioning Problem Fixed
Post by: Markjay on 15 September 2007, 00:09:38
Mine is a 2001 2.6 CDX as well, and I had it for 6 years now...

It didn't seem to mist-up worst than other cars.

But the climate seem to have a life of its own... this is in spite of running the rest procedure and also having disconnected the battery on a couple of ocassions (for unrelated reasons). I never quite worked it out. I now put it on either LO or HI and nothing in between, and set the fan sped manually.

Title: Re: Omega Air Conditioning Problem Fixed
Post by: Mike Collins on 15 September 2007, 08:10:19
Is the sampling fan in the panel running to pull cabin air over the sensor?
Title: Re: Omega Air Conditioning Problem Fixed
Post by: Marks DTM Calib on 15 September 2007, 08:20:50
Quote
Mine is a 2001 2.6 CDX as well, and I had it for 6 years now...

It didn't seem to mist-up worst than other cars.

But the climate seem to have a life of its own... this is in spite of running the rest procedure and also having disconnected the battery on a couple of ocassions (for unrelated reasons). I never quite worked it out. I now put it on either LO or HI and nothing in between, and set the fan sped manually.


Updated firmware required  :y
Title: Re: Omega Air Conditioning Problem Fixed
Post by: TheBoy on 15 September 2007, 10:04:18
Quote
Mine is a 2001 2.6 CDX as well, and I had it for 6 years now...

It didn't seem to mist-up worst than other cars.

But the climate seem to have a life of its own... this is in spite of running the rest procedure and also having disconnected the battery on a couple of ocassions (for unrelated reasons). I never quite worked it out. I now put it on either LO or HI and nothing in between, and set the fan sped manually.

Worth trying later software on the climate panel - I don't have a facelift, but others whom I've done it for have said there is an improvement.  I get a feeling we didn't update your panel due to your battery having a bit of a moan ;)
Title: Re: Omega Air Conditioning Problem Fixed
Post by: Markjay on 15 September 2007, 14:49:15
Quote
Quote
Mine is a 2001 2.6 CDX as well, and I had it for 6 years now...

It didn't seem to mist-up worst than other cars.

But the climate seem to have a life of its own... this is in spite of running the rest procedure and also having disconnected the battery on a couple of ocassions (for unrelated reasons). I never quite worked it out. I now put it on either LO or HI and nothing in between, and set the fan sped manually.

Worth trying later software on the climate panel - I don't have a facelift, but others whom I've done it for have said there is an improvement.  I get a feeling we didn't update your panel due to your battery having a bit of a moan ;)


... I thought you've done it last time...?  :o
Title: Re: Omega Air Conditioning Problem Fixed
Post by: TheBoy on 15 September 2007, 19:18:37
Quote
Quote
Quote
Mine is a 2001 2.6 CDX as well, and I had it for 6 years now...

It didn't seem to mist-up worst than other cars.

But the climate seem to have a life of its own... this is in spite of running the rest procedure and also having disconnected the battery on a couple of ocassions (for unrelated reasons). I never quite worked it out. I now put it on either LO or HI and nothing in between, and set the fan sped manually.

Worth trying later software on the climate panel - I don't have a facelift, but others whom I've done it for have said there is an improvement.  I get a feeling we didn't update your panel due to your battery having a bit of a moan ;)


... I thought you've done it last time...?  :o
Can't remember tbh...
Title: Re: Omega Air Conditioning Problem Fixed
Post by: Markjay on 16 September 2007, 14:54:28
Quote
Quote
Quote
Quote
Mine is a 2001 2.6 CDX as well, and I had it for 6 years now...

It didn't seem to mist-up worst than other cars.

But the climate seem to have a life of its own... this is in spite of running the rest procedure and also having disconnected the battery on a couple of ocassions (for unrelated reasons). I never quite worked it out. I now put it on either LO or HI and nothing in between, and set the fan sped manually.

Worth trying later software on the climate panel - I don't have a facelift, but others whom I've done it for have said there is an improvement.  I get a feeling we didn't update your panel due to your battery having a bit of a moan ;)


... I thought you've done it last time...?  :o
Can't remember tbh...

Never mind, we'll get it sorted next time  ;)