A/C died!

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poprivet

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Re: A/C died!

Postby poprivet » Thu Aug 20, 2015 7:13 am

Mine has metric threads, I think your car is slightly newer then mine so I'm suprised yours is imperial. However, I would keep hold of it if I were you as I can see the supply of these only getting worse.

Rebuilt units seem to have a poor reputation, the Harrison ones were used on many different cars including numerous American ones, some Audi's and even tractors and heavy plant so I'm suprised that some enterprising engineering firm hasn't yet come up with a cost effective solution.

Delphi rebuilds are available but at a cost of over £300 + the cost of gassing and I quite like the look of the Retroair alloy ones http://www.retroair.com/jaguaraircondit ... rades.html but I am reluctant to import one without a lot more knowledge about them.

Another option is perhaps the Sandon unit used on the later XJSs although pipework and hoses would need some modification.

Anything is possible, but it's easy to get carried away with the cost when in reality I have been managing quite well on just fresh air alone this summer!
1988 3.6 XJ-S coupe
'Remember that the value of your investment can plummet as well as fall'

Brakebuster
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Re: A/C died!

Postby Brakebuster » Thu Aug 20, 2015 7:26 am

you miss understand, mine is metric

I have a spare brand new NOS unit that has imperial threads, its only the mounting bolts , the fittings are exactly the same

as you say , plenty of modern alternatives, but how they are adapted can sometimes be tricky

or just open the window I suppose :wink:

BB
1989 5.3ltr V12 XJS Coupé FULLY RESTORED
2004 2.1V6 X-Type Saloon in platinum silver for the good wife
1994 3.2S XJ40 in Morocco Red with Doeskin interior

used to have
1999 4ltr Sovereign XJ8 in Seafrost

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poprivet

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Re: A/C died!

Postby poprivet » Thu Aug 20, 2015 10:10 am

If I should re-instate the A/C, and that is by no means certain, I have been thinking on another modification.

I believe on some earlier XJSs, the aux cooling fan ran whenever the compressor was running, many new cars do this including my Citroen. Additional cooling should reduce the pressures in theory, in my mind no bad thing especially if using 134a gas.

Anyway, at a point in history, Jaguar decided this wasn't necessary and the aux fan only ran when the coolant temperature rose above a set limit, (I speak based on my '88 3.6 your car may be different).

Looking at the wiring diagrams, it seems fairly easy to re-instate the system to allow the fan to run. Below I have cobbled together the two seperate diagrams to show how to link it. The pectron unit (small blue relay looking thing on the left inner wing by the fuse boxes), still has the unused diode that is needed to ensure that the aux fan can run-on if necessary when the engine is switched off. All that is needed is to cable this up to either the compressor clutch relay.

I say again that at the moment this is untested, so if you choose to follow a similar path please check your car and wiring first, don't blame me if all your wiring catches fire!

Before I get too carried away with it though i would be interested in others thoughts on the subject, especially if it would be an advantage for a 134a converted system.

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1988 3.6 XJ-S coupe
'Remember that the value of your investment can plummet as well as fall'

ptjs1

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Re: A/C died!

Postby ptjs1 » Thu Aug 20, 2015 1:53 pm

Pop,

Certainly worth ringing David Marks. I understand he routinely does this modification on many cars that they see.

Paul
1995 XJS 4.0 Convertible
1980 XJ-S Pre-HE
Jaguar 4.2 Supercharged engine (but not with a Jaguar body..)

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piman

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Re: A/C died!

Postby piman » Thu Aug 20, 2015 5:15 pm

Hello Pop,

surely when the car is running normally the forward motion will provide the cooling, and in slow or stop go then the cooling fan will switch in? Is there any real benefit? Never having been involved in automobile refrigeration, do they have a high pressure switch as protection?

Alec
Mk 2 3.8 (long term restoration), MK1 Triumph 2.5 P.I.,2.5 X Type Estate, 564 Hymer Motorhome

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poprivet

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Re: A/C died!

Postby poprivet » Tue Aug 25, 2015 7:53 am

Hi Alec, there's no high pressure cut off switch, just a safety relief valve. The standard R12 system does cope well, my questions were with a R134a refit where pressure characteristics are different.
1988 3.6 XJ-S coupe
'Remember that the value of your investment can plummet as well as fall'

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poprivet

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Re: A/C died!

Postby poprivet » Tue Aug 25, 2015 8:15 am

With a rainy day and not much else to do I thought I would clean up the area where the compressor used to reside. Lots of space now that the hoses and metalwork are out of the way.

I did notice that the wires feeding the electrical spade connectors were frayed and weak so I cut them off and stripped back the insulation to solder new ones on, however the copper had oxidised quite badly. Mindful that I couldn't cut them back too far else they would be too short I released the loom so it could be unwrapped. This loom which runs tight across the front of the engine also feeds the ignition coil, amplifier and a couple of earth connectors and the route it takes meant taking the coil out and carefully feeding the various connectors around various pipework.

I'm glad I did really, a couple of pins on the amplifier were rusty and the earth connections were showing corrosion, although still working ok, I'm sure it wouldn't have been long before problems had started.

Unwrapping the loom reveiled a diode wired across the compressor connectors, not shown on the schematic wiring diagram! As all the connections were suspect, I renewed the wiring back to and including the diode. Before re-wrapping, I added a connection point just in case I decide to do the aux fan mod described earlier.

My back is killing me now, bending over the car wing is getting more difficult as the years are passing by :(
1988 3.6 XJ-S coupe
'Remember that the value of your investment can plummet as well as fall'

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piman

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Re: A/C died!

Postby piman » Tue Aug 25, 2015 9:47 am

Hello Pop,

pressure relief valve, that sounds a poor answer to over pressure as it loses gas, just for the sake of a pressure switch?

I'm aware of the different gas but that doesn't alter the condenser cooling requirement, and unless you spend all your time in slow stop go traffic I see little benefit of having the fan switched with the compressor. A better solution is to switch the fan with a condenser temperature sensor.

Alec
Mk 2 3.8 (long term restoration), MK1 Triumph 2.5 P.I.,2.5 X Type Estate, 564 Hymer Motorhome

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poprivet

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Re: A/C died!

Postby poprivet » Sat Oct 03, 2015 4:18 pm

I've been shopping :)

Image

Arrived in a box, rebuilt in Texas. I've swapped over the pressure switch, baffle and labels ready to go in (Don't worry, the ends will be capped!). Apart from leaking, the old compressor shaft had excessive side play and the clutch was grooved beyond repair.

Don't ask what it cost, all I can say is life is quite difficult without one leg and one arm :cry:
1988 3.6 XJ-S coupe
'Remember that the value of your investment can plummet as well as fall'

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poprivet

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Re: A/C died!

Postby poprivet » Mon Oct 05, 2015 3:15 pm

Jim pressurised the system with 8bar of nitrogen on Friday, today it was still holding on 8 so it's good news.

The car is on sorn now as I've no trips planned and there are a number of other maintenance issues I want to attend to over the coming months, write ups as and when they occour.

In the spring I will have the a/c system gassed up and ready for the new season :D
1988 3.6 XJ-S coupe
'Remember that the value of your investment can plummet as well as fall'

ptjs1

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Re: A/C died!

Postby ptjs1 » Mon Oct 05, 2015 6:03 pm

Pop,

Good that you've been able to source the compressor, albeit at a cost, I'm sure!

I realise that you might be sorn'ing the car but, as you know, the running of the aircon keeps your seals lubricated. If you leave it now until the spring before gassing, you might well be looking at more cost to replace some seals as they may well go hard over the winter if unused.

I had to get mine re-gassed and two compressor seals fitted recently, all because I didn't really use the aircon much after it was done a year ago.

Cheers

PAul
1995 XJS 4.0 Convertible
1980 XJ-S Pre-HE
Jaguar 4.2 Supercharged engine (but not with a Jaguar body..)

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poprivet

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Re: A/C died!

Postby poprivet » Mon Aug 26, 2019 2:12 pm

4 years on.

I had forgotton to update this thread at the time but I did buy and fit a re-con Harrison compressor (from a mainstream Jag parts supplier) and my Med sailing chum oiled and re-gassed the system. All has been well the last four years until the other week I noticed that the compressor was making a slight rumbling noise. That has now developed into a full blown grinding, it sounds like a bearing has failed.

Oddly, it is still cooling with a perfect icy blast but the noise is terrible so I have pulled the A/C relay and instigated the trick to keep the re-circ flaps closed so at least I have fresh air.

I'm not sure I want to go through the whole expensive and difficult to get at procedure again. Maybe I will get the gas recovered, remove the compressor and think about it for a while.

Al
1988 3.6 XJ-S coupe
'Remember that the value of your investment can plummet as well as fall'

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J44EAG

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Re: A/C died!

Postby J44EAG » Mon Aug 26, 2019 8:00 pm

Could you not fit a more common, less expensive, mainstream compressor, Al?

Mike
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ptjs1

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Re: A/C died!

Postby ptjs1 » Tue Aug 27, 2019 11:50 am

I bought a Sanden one recently for my 4 litre as I've lost my gas somehow through the front seal of the compressor. I picked it up for about £220 (I think) from SNG. I did think about rebuilding my existing one (and still might do that...) but decided that when I changed the £20 seal, I'd probably find wear in the bearings etc etc so could see that it was probably easier to get a new one at that price. I'll get around to fitting it soon!

I know there may be fitting changes etc, but can see how it must be quite feasible to fit the later Sanden unit to your car.

Good luck

Paul
1995 XJS 4.0 Convertible
1980 XJ-S Pre-HE
Jaguar 4.2 Supercharged engine (but not with a Jaguar body..)

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poprivet

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Re: A/C died!

Postby poprivet » Wed Aug 28, 2019 2:48 pm

I've seen these kits before, which use a Sandon and include just about everything.

Image

https://www.ebay.co.uk/itm/Jaguar-XJS-3 ... 3471820694

I could fit it myself and vacuum test it although I would have to find someone to gas it up. But can I justify the cost?

Al
1988 3.6 XJ-S coupe
'Remember that the value of your investment can plummet as well as fall'


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