Climate Control just not upto the job!

[boywithapassat]

I got a little problem with the cold air in my passat, it just doesnt seem to put the chills down my spine anymore!!!

Ive baught on of those low pressure re-fridgeerant pressure checkers and it all seems to be in the green but still its not really cold air comin out of the vents.

just wondered if there were any checks i could do to see what the problem is? is it worth pulling the glove box out to see if the heat exchanger is cold?
any tricks of the trade? I dont want to go too deep into it as all those chemicals scare the bejezzus out of me!

or shall I just drag it into a garage? I want it done fairly soon so I dont miss the one week of good weather we call summer!!

[caldirun]

I got a little problem with the cold air in my passat, it just doesnt seem to put the chills down my spine anymore!!!

Ive baught on of those low pressure re-fridgeerant pressure checkers and it all seems to be in the green but still its not really cold air comin out of the vents.

just wondered if there were any checks i could do to see what the problem is? is it worth pulling the glove box out to see if the heat exchanger is cold?
any tricks of the trade? I dont want to go too deep into it as all those chemicals scare the bejezzus out of me!

or shall I just drag it into a garage? I want it done fairly soon so I dont miss the one week of good weather we call summer!!

Have you had a cam belt change since it last worked? they seem to leave the compressor clutch wire disconnected when they move the rad forward to access the belt cover. If the compressor pulley is rotating but not the boss you have found the fault.

[boywithapassat]

well! would you beleive I have! at the main dealers none the less! Ill go and check it now, watch this space!.....

[passat 130 tdi]

tip i followed once was took out the glove box , place an old kettle with no lid on the floor , switch engine on ,run aircon on full blast for 20 minutes on recirclating air with boiling steam of kettle being sucked into the vent , watch for water running from the aircon drain outside the car ( not sure where it is on the passat ) this shows all is well , then after 20 minutes , take the car for a run and with the vent set to fresh air run the car for a further 20 minutes , last 10 minutes set air con off and turn heat up to maximum , this dries out the system to avoid smells ,kills all living bacteria inside the exchanger and vents , it worked for me on my toyota , made air con freezing and got rid of the pond smell . The tins of chemicals you buy do the same thing really .

the smell can be avoided by turning off the air con 5 miles before end of journey and crank up the heat a bit to dry out the air vents and similar areas , its this dampness that makes for bacterias and smells.

[boywithapassat]

right,

had a quick look and it occured to me that Im not sure what im lookin for! which one of the many ancillariers of the belt is the aircon?
is it the one with a belt of its own?
lower LHS?
to get the best look i think ill need to take of the plastic pan under the engine bay, is that right?

I think im more or less there but im on holiday so have no tools with me so shall further investigation on return home.

It also occured to me that there is no change in engine tone on idle when i turn the AC on, so your pump clutch theory could be right as theres no aditional strain on the engine? what you think?

[snapdragon]

You really need plugging into a vagcom, the self diagnosis is rather good. Might be a pressure switch or leak. I suspect your compressor is not working, may not even be being told to by the control unit due to a fault elsewhere.

[boywithapassat]

but I had service at main dealers not to long ago, wouldnt of it shown up when they did their diagnostic? I mean they told me lots of other stuff from doing it.

[caldirun]

but I had service at main dealers not to long ago, wouldnt of it shown up when they did their diagnostic? I mean they told me lots of other stuff from doing it.

I have Vagcom and it showed no faults when my clutch wire was off. If you look down past the condensor fan on the left of the rad (this should be running if you are on AUTO climatronic or aircon on, non climatronic ) with a torch you will see a black boss in the centre of a multi-vee pulley, this is the drive for compressor shaft and should rotate when the clutch wire has 12V on it.
There are two green connectors, one next to the pulley and one on the power steering reservior bracket, mine was disconnected at the reservior. I did notice the difference in tickover speed as the aircon compressor cut in when I attached the wire, so you are correct in this.
I hate to say this but its lucky you dont need aircon at the moment (sorry)

[snapdragon]

but I had service at main dealers not to long ago, wouldnt of it shown up when they did their diagnostic? I mean they told me lots of other stuff from doing it.

Not unless they specifically checked the HVAC control unit, there are up to 16 ECUS which have to be checked individually which would take about 15 minutes, so they usually just do Engine and Autobox.

There is other stuff that can be checked with VAG COM, and output tests can be used to move flaps, cycle compressor, check voltage to compressor and check status of a myriad of sensors etc...

[TheMadhatter]

I would find an air con specialist to check it out.

My dad has a Seat Alhambra and a while ago the air con stopped working, much like yours. Took it to the main dealer and they "recharged" it.

It worked for 3 days and then stopped. Took it back again and they gave the system a good going over and pronounced there was a leak in part of the system deep in the dash, £500 to fix.

When I took my car to independent VW specialist my dad asked if there was an independent air con specialist that was good in our area, one was recommended and he came round in his van and had a look a the seat.

After pressurising the system to 9bar he and finding no leak, and then doing a recharge, he said that it had not been recharged properly by the Seat dealer and that was why it was not working.

He also said that this was something that he saw a lot of, the main dealers just don't do the recharge properly as it takes time, so they wander off and do something else rather than doing the recharge properly. It took the specialist about 2 hours to do the recharge for £60. The air con has worked perfectly ever since.

He said that the air con needs to be recharged about once every 2 to 3 years to keep it working at peak performance. So if you cant' find that clutch lead find a good independent specialist.