I recently had the cam cover gaskets on my V12 replaced by a local workshop, due to massive oil leakage.
Apart from a few elbow dents in the front fenders, they did a decent job on the engine. No more oil leaks are detectable.

However, in order to remove the RH cam cover, they had to tilt the aircon compressor forward. Otherwise the cover could not be removed.
More than one mechanics have worked on the car and presumably one of them has evacuated the aircon system by loosening a few hose connections, but forgot to mention this to the other mechanic.

When I picked up the car, I noticed that the airconditioning wasn't working anymore, which I told the shop owner.
He then started his quest for the cause of the problem, without first checking if the system was perhaps empty.

Long story short: He couldn't find the problem, other than the clutch not engaging and referred me to an airconditioning specialist.
The specialist now found that the shop had severed and wrongly reattached several wires to the compressor.
He has restored the wiring to the compressor to its previous state, but cannot get a 12V plus on the yellow-green wire. All fuses are in tact however.

I suggested to go the "quick and dirty" way and lay a new 12V switched plus with a 15A inline fuse to the compressor.
He tried that and behold: the clutch engaged.
The specialist however is worried that this kind of fix will bypass security features in case there is a system leak or other failure.

What do you specialists think of this?

 

It shouldn't be necessary to resort to a quick and dirty solution. The circuit isn't complicated; it shouldn't be all that had to find the fault and restore things back to original operating condition.

I don't have a wiring diagram to cover your exact model but I've found that these cars are usually wired the same as the XJS.

I'm too blurry eyed at the moment but later, if you'd like, I can post some info that you can pass along to your AC shop

Cheers
DD

 

More than one, UGH!!!!

1. Render dents from elbows.? A professional would place fender cloths on each one. More like belt buckle dents, I think!!! Unacceptable/

2. Crack a line to evacuate the R134A! No ! One it cost money. Two it pollutes the atmosphere. unacceptable. Use a proper hose and guage plus a vacumn pump. When the work is done restore the R134a to the system.

3. Cutting wires is No/no!! or at a minimum, splice them back properly. Unaccptable.

4. A jump wire OK to test, but not as a fix. Figure out the connections the right way. and, aye, It may override a built in. I did it once to force the compressor to engage and allow a recharge. I got away lucky, It merely frosted the matrix in the cabin. I restored the wire to 'stock" and the unit continued to cool.

Does the S57 Jaguar schematic clarify the wire order ? It is a GM Harrison compressor. but more than on means of protection has been used.

Carl

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yeah, i know....never let a German guy work on a British car ;-)

As I own a body shop, the dents are an easy fix for us, but they shouldn't have been made to start with.
They actually did use fender cloths / blankets, but obviously it wasn't enough.

We got the wiring sorted by the way. Turns out the german blew the inline fuse to the amplifier... With the original schematic, we were able to reconstruct the original wiring and the clutch engages again with pressurized nitrogen in the system.

Found the clutch to have a minor leak though, so filling is not an option without repairs.
As the Harrison A6 is not readily available over here in the right configuration ( pre july 1986), I ordered a replacement compressor from Behr Hella. This one is actually made for R134a and is interchangeble.

Then I will order a rebuild kit for the original Harrison and rebuild it for keeping or selling. Depends on how well the Hella unit works.

Releasing 134a into the atmosphere is a definite no-no in my book. I actually was trained in F-gasses a while back, so i know about the impact of aircon gasses to the atmosphere. The German had an apprentice work on my car and he messed up big time. I would have first checked the charge, then the fuse then the rest... The apprentice immediatly assumed he had damaged a wire when he tilted the compressor....i guess assumption really is the mother of all mess ups then....