So. This morning I am heading into work. I work at General Motors, Vehicle Engineering Group in Michigan. The car starts up, I am driving in, I get a cup of coffee at the local ma and pa shop on the corner. Get to work, no problems.

Day comes to an end, I walk out to the car, throw the key into the ignition, pump the throttle twice (for some reason it starts better after doing that when it's sat for a few hours), turn the key and i hear this HORRID squealing coming from under the hood.

For those who've read my previous thread about the AC clutch removing itself from the AC Compressor? Yep. She was locked up tighter than a frog's ***. The engine and alternator were spinning the belt on the pulley that would not move of the AC Compressor.

I don't have air in the car, been too hard finding someone who will refill a R12 system so I could care less if it's there. But I need that compresser there so I can run the belt that is running the alternator.... There's too much junk in the way to just go straight from the crank to the alternator so.

IF ANYONE has any suggestions as to how to just flat out by pass the AC compresser, I would love to hear them.

 

I found myself in that situation once (seized compressor due to my own negligence) and I simply unplugged the wire to the clutch (inline spade connector). It's electromagnetic; no power, no apply.

That let the pulley spin freely until Spring when I had to get a new compressor. In California one does NOT go without AC in Summer.
(';')

 

What sort of maintenance do you carry out on the AC Compressor to make sure it doesn't seize?

There doesn't seem to be any grease point anywhere.

 

6 cylinder car? If it is a V12, the alternator is not run by the aircon belt, unless it has been modified.

If LnR's solution does not work, if the car has a standard V12 belt layout, you can just cut off the belt. It only goes round an idler/adjuster pulley apart from the crank and the compressor itself.

Greg

OB, no grease points on the compressor, AFAIK.

 

As I think the Air Con, which I've never used, will probably need re-gassing after all this time (since 1990!)

If I took the Belt off, would it make a significant difference to the performance?

Would the heater and blower still work ok?

It must be one of the Best Heaters that I have seen on any other Car.

Although I'm aware the Air Con could be useful @Pjts Its not worth the cost of having it re-gassed at the moment, what with all the other bits and pieces that I've got to buy.

So not having the Air Con working, is no big deal as far as I am concerned but maybe I'll get it done later.

 

OB, replies to your questions in red:

As I think the Air Con, which I've never used, will probably need re-gassing after all this time (since 1990!) It will and lots of other expensive bits too!

If I took the Belt off, would it make a significant difference to the performance? No, but you could take off the flexible pipes, compressor (tape up any electrical connectors), dryer (the cylindrical thing across the front top of the rad), and condenser rad too, and save a ton of weight and give better engine access! AND improve airflow through the rad!! You would just need to rig up a couple of rods to hold the top of the oil cooler rad to the radtop cross panel (which the condenser does otherwise). Now is the time to do it as everything is out of the way!
If there is a wire which branches onwards from the compressor, leave it connected up and just tape off the compressor connector..

Would the heater and blower still work ok? Yes, as they do now; however that is!

It must be one of the Best Heaters that I have seen on any other Car. The one advantage of the XJS V12's heat creating ability!

Although I'm aware the Air Con could be useful @Pjts Its not worth the cost of having it re-gassed at the moment, what with all the other bits and pieces that I've got to buy. Too right, not really needed in a droptop. A coupé, that is different! I cook in mine without it.

Greg

 

Looked at the car in your Garage, and I assume that is the beast you are having moments with?????.

It is a V12, and a Lucas ignition car.

The ORIGINAL set up has the alternator down the bottom, and driven by its own belt.

The A/C belt went from the crankshaft pulley, A/C, Air Pump (or idler in our market), so removing that belt will ONLY stop the A/C and air pump from working, big deal, NOT.

HOWEVER, and this is where eyeballing THAT car will be required.

Some people have replaced the air pump with a higher output alternator (AC Delco in the USA), and then YES, the alternator will cease operation if that belt is removed. This is NOT how the factory made the car, it is an owner upgrade.

So, if in fact, your alternator is "up top" then the double row bearing inside the A/C clutch can be replaced, and it can continue to be the "idler" as it was prior to the event.

If the item "up top" is still the air pump, then simply cut the belt and enjoy the drive, until the urge to fit a compact compressor takes over.

 

Just read this at work. Took a "smoke break" that so many do here, went out and popped up the hood, found the wire, unplugged it, BINGO!!!!

Motor started and the compressor spun freely!!!! Thank you VERY MUCH!!!

And Greg, I am not sure what the belt is going around. The one that comes off my crank going to the AC compressor is going to something that looks either like an alternator or another compressor of some sort. I see wires going to it as well.

 

I do (or did) see the alternator down below. The one that is up top I will assume is the air pump then? Anyway I unplugged the compressor (Says General Motors Corporation on the sticker) and it freed up. Now my dilema is figuring out how to get the Jag AND the Audi home after work today....

 

The shaft seal had been leaking (oily, dusty) all Summer but I "didn't have time" to fix it so the system ran dry. That wouldn't normally have been a problem but unknown to me the low pressure switch was also faulty and allowed the compressor to continue spinning until it seized.

If the clutch isn't engaged the pulley spins forever or until its bearings give out. To my knowledge there is no maintenance other than keeping the system charged, and therefore keeping oil in the compressor. If you're not gonna do that you need to unplug the clutch.
(';')

 

You are very welcome.

Actually, the compressor DOES NOT spin, which is the point because it can't, as it's seized. The clutch is disengaged allowing the PULLEY to spin freely on the shaft.
(';')
Elinor B

 

Well in June my clutch disk flew off and messed up my radiator. When it broke free it got wedged between the spinning shaft on the pulley and the hood, thus melting the steel to the point of it flying off and dislodging the water pump belt.

Whatever unplugging the compressor did, all I know is the pulley is now spinning. Now my next question is do I need the air pump that is being driven on that belt for anything either? Like someone mentioned earlier in this thread, I might just remove everything associated to the AC and lose some weight and gain more air flow through the engine compartment and radiator....

 

You had a real mess, didn't you!

Mine only stopped turning because I stopped at an intersection and engine RPM dropped enough for the compressor to seize. I had to pop the hood to find the squalling cat! I don't even want to think how far I could have driven it before molten metal began flying around the engine bay.

Yes, the pulley is spinning free because whatever was left of the clutch is disconnected and therefore disengaged. If you have no need for AC where you live, chuck the lot! If you want/need AC, consider alternative refrigerants like for example Propane, HC-12a. I have it in one car (R-12 OEM) and when Nix needs a charge she'll get it too. It's Worlds better than 134 and actually cools better than Freon in my experience.

I can't comment on your air pump except that I know California requires that it be working for emissions requirements.
(';')

 

Ummm....

Legal Status of HC-12a ®, DURACOOL 12a ®, and OZ-12 ® | Alternatives / SNAP | US EPA

According to this, the EPA (Environmental Protection Agency) in the USA has banned this product for many, many uses. It specifically prohibits this product from being used in any motorized vehicles, as it is highly flammable. I can't imagine California is any less stringent in regulations (HA!) than the EPA. How the heck did you manage to get it into your AC system?

Good 'ol over-reaching EPA, they wonder why they are getting disliked. Personally, I hope it gets defunded, though now-days it is starting to state that it has the ability to collect fees directly to its program.

 

I live in South Eastern Michigan. And I do not plan on driving the girl in the winter so. The belt I believe will be chopped, and the pieces removed. On a side note. I live in Chicago for a while too where they had a yearly emissions check. At the time I had a 1990 Olds Toronado. Removed the EGR, removed the cat, put hotter plugs, bigger exhaust and ran premium gas in it. When it came that time of year to get it checked, it still passed.... with ALL OF THE EMISSIONS JUNK REMOVED!!!! And on top of that, was getting about 32 MPG.. I could go on... :-)

 

I am going to just flat out remove the AC system if I can. I will use the 270 or 280 air conditioning system if it gets too warm here. 2 windows down, and hauling a$$ at 70 or 80.....

 

That's quite a laugh because ALL refrigerants are flammable. However, I didn't not know it was now illegal to use in automotive applications. I'm sure we'll take that under advisement.

Good Ole DIY. Husband found a source online said to be specifically formulated for automotive AC and we went from there. is your friend. We do most things ourselves, as it saves Tons of money that would otherwise buy someone (DuPont) another annuity. We have other things we would rather do with it.

The agency everyone loves to hate.
(';')

 

Hi Greg

You must be Telepathic!

While I was getting the Fan Shroud out, I was looking at The Condenser Rad (which I believe is the very thin one in front of the Main Rad) and I was thinking what do I need that for?

If only that Rad wasn't there, I would get much more Airflow through the Main Radiator and as an added bonus the Engine Compartment would be easier to keep Clean.

Plus it would give easier access to the Main Rad and Hoses, if I had a burst Rad Hose while out on the road, The list goes on......

But then I thought, Don't touch it! until I have spoken to Greg!

 

Mine seized up again Saturday morning being unplugged. So I pulled out the knife and just cut the belt. I figure eventually I want to redo the exhaust too with bigger diameter pipes to give it less of a lawn mower sound so, the air pump will come out with the rest of the AC system. No need for it where I live so.

 

DIY, the ONLY way to go! That answers the question of how you got HC12a in the system, and I shall say no more about it!

The compressors used in many of the XJS's were also, as you noticed, made by/for GM vehicles. They are not that expensive, relatively speaking for Jaguar parts, about $250 at Napa. I'm sure you may even be able to get it rebuilt for less. OTOH, like has been stated, you can save yourself some weight, up the gas mileage, and make future spark plug changes much easier by removing the unusable compressor!