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Air-con not cool!


boaterboy
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The air-con on my TD5 does not seem to cool the cabin as much as it used to. The air coming out of the vents seems relatively warm. I'd appreciate any thoughts on what might be the problem - and the solution. Thank you in anticipation.

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The air-con on my TD5 does not seem to cool the cabin as much as it used to. The air coming out of the vents seems relatively warm. I'd appreciate any thoughts on what might be the problem - and the solution. Thank you in anticipation.

First you need to establish that the A/C compressor is actualy turning. If it is and the Air Off is warm it is possibly a control problem. If not it is much more likely to need a recharge.

A slight loss of refrigerant can cause poor performance and still allow the compessor to run but with the sytem on your vehicle it is unlikely.

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Out of curiosity how often have you had the unit regassed?

We have had the same issue with the saab and mercs with aircon and over the years the aircon decreases and you get warmer air. Solved it every time with a simple regas by a specilist cost about £60 for the last one from memory and he even came out to us which was convient :)

Hope this helps.

Ryck

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Out of curiosity how often have you had the unit regassed?

We have had the same issue with the saab and mercs with aircon and over the years the aircon decreases and you get warmer air. Solved it every time with a simple regas by a specilist cost about £60 for the last one from memory and he even came out to us which was convient :)

Hope this helps.

Ryck

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The vehicle is 2002 and to date the air-con has received no attention, including regassing, other than being switched on regularly and frequently (at least once a week) in the belief that that keeps the seals 'lubricated'.

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Im not sure of a figure but I would say you should certainly be needing a jumper with it pumping out cold. Our Saab at one point spat out the odd condensed ice ball from water in system that had been condensed to freezing.

Cheers

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I've heard 6 degrees mentioned.

For interest, the average air con system will deliver a temperature dependant on outside air temperature and relative humidity. At 1500 Rpm with the engine at full operating temperature and a relative humidity of 60-80% you should be measuring the following 36" from the outlet.

Ambient 20-24 Delivery temp 4-14c

Ambient 25-29 Delivery temp 9-19c

Ambient 30-35 Delivery temp 20-27c

If you have climate control a small amount of heated air is introduced to give a constant temperature to a minimum of 16c The reason for this is that there are documented cases of farm workers spending hours in an air conditioned cab and collapsing from thermal shock when leaving it, sometimes with fatal consequences.

The system using R134a refrigerant will loose a low percentage of refrigerant through the rubber pipework it is impossible to prevent this and for obvious reasons you can't use solid pipework like your domestic fridge.

As for quick fit, ask them if they know any of the above and ask to see their refrigerant handling certificate.

You always will get what you pay for.

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Good to keep this post running for updates as I was about to post "Lack of A/C-common causes please"

Got my '94 300Tdi Disco back in January and the A/C appears not to work, though I think some cooler

air comes through the vents compared to ambient ram air temp.

Have checked fuses and wondered if it was a simple regas required.

One point please guys, can you hear an audible click from the compressor clutch when turning the system

on and off ?

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Got my '94 300Tdi Disco back in January and the A/C appears not to work, though I think some cooler

air comes through the vents compared to ambient ram air temp.

Have checked fuses and wondered if it was a simple regas required.

One point please guys, can you hear an audible click from the compressor clutch when turning the system

on and off ?

before you take it to be gassed, check the alloy pipe that runs along the rh inner wing. it's held to the wing by a "p" clip just by the coolant tank/fuse box. when i took mine to be done last year, the pipe had corroded, and fell apart on this point - fitted what looked like a good 2nd hand one, that did the same - ended up buying a new pipe and receiver/drier (they are dead after 10 mins exposed to air) air con is now nice and cold.

5 deg C at the vents was measured.

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Just visited my chum who's Discovery ('95 300Tdi) was having air con problems. As it's in Spain it's pretty important as the temp gets quite warm!

He got it re-gassed at a local garage and lovely cold air now comes out but he now has a problem with the fan switch.

We took the fascia apart and found the switch wasn't working on a couple of positions and the connector on the back had overheated and gone brittle.

We took them both out, cleaned up the switch contacts and got one more working. We also took the wires out of the connector and put them onto the contacts at the back of the switch - not ideal but with insulating tape to stop them shorting at least he has 3 out of 4 speeds on the fan. Problem is, what is the switch part number as we can't find it anywhere (even Microcat), and does anyone know what the connector number/type is so we can do the job properly?

Thanks

Malcolm

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Just visited my chum who's Discovery ('95 300Tdi) was having air con problems. As it's in Spain it's pretty important as the temp gets quite warm!

He got it re-gassed at a local garage and lovely cold air now comes out but he now has a problem with the fan switch.

We took the fascia apart and found the switch wasn't working on a couple of positions and the connector on the back had overheated and gone brittle.

We took them both out, cleaned up the switch contacts and got one more working. We also took the wires out of the connector and put them onto the contacts at the back of the switch - not ideal but with insulating tape to stop them shorting at least he has 3 out of 4 speeds on the fan. Problem is, what is the switch part number as we can't find it anywhere (even Microcat), and does anyone know what the connector number/type is so we can do the job properly?

The switch is BTR 6494

Thanks

Malcolm

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Unfortunately not. We'd already bought one like that but when we took the fascia off it's not the one. The one that's in situ has the contacts vertically at the back and the mechanism actually slides horizontally as opposed to swivelling like this one.

It's got "siemens" stamped on it plus a load of numbers.

I've been told you have to buy a complete fascia to get it - but hope that's not the case.

Malcolm

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Thank you for all the earlier comments, as I mentioned earlier I aim to get my air-con regassed just as soon as I get time.

Urgency now gone as hot spell over for a while it seems - using heater, which works fine!

A couple of questions have come to mind, however.

If there are no leaks in the system, why should regassing be required?

Does the coolant, which is in a closed system, degrade resulting in poor cooling performance?

If it does not degrade, does poor cooling performance therefore equate automatically to a leak in the system?

Is not the air-con system a refridgerator, in effect?

If so, why do domestic 'fridges, which run for years and almost non-stop, never need regassing?

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Thank you for all the earlier comments, as I mentioned earlier I aim to get my air-con regassed just as soon as I get time.

Urgency now gone as hot spell over for a while it seems - using heater, which works fine!

A couple of questions have come to mind, however.

If there are no leaks in the system, why should regassing be required?

Does the coolant, which is in a closed system, degrade resulting in poor cooling performance?

If it does not degrade, does poor cooling performance therefore equate automatically to a leak in the system?

Is not the air-con system a refridgerator, in effect?

If so, why do domestic 'fridges, which run for years and almost non-stop, never need regassing?

As I said earlier in this post, the refrigerant R134A escapes through the rubber hoses. You will not find rubber hoses on a domestic fridge because it does not need them (no bouncing along the road). On truck mounted fridges they use copper vibrasorbers instead of rubber but they don't downscale particularly well. In any case, all the different fridge applications use different refrigerants. I have worked in Transport refrigeration and Air Conditioning for 25 years and in that time the hose problem has never really been sorted and in fact became worse when 134A replaced R12 in vehicle systems.

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