[Tony Rama]

Update:

Advice to get a new compressor and fit myself was insufficient since there was no instruction on adding oil, how much, checking for swarf in the system etc etc.

Went to another company. They diagnosed the same fault in the compressor internal valve. (£60)

Supplied and fitted new compressor, including testing and VAT. (£768).

Since found out that modern compressors have a solenoid valve plugged into the side which fails easily if not regularly used. If I had had the knowledge I could have replaced it myself for about £30 and then paid for the re-gas.

But is was not to be......

Moral of the story: My understanding is that modern air compressors have this solenoid valve to micro regulate the gas flow for the purpose of fuel saving rather than just on/off with the clutch. So given that they are more economical to use, it seems it is best to keep the climate control permanently on.

PS. Stretch belt was original dated 22 06 2010 and 155k miles. Replaced it with nice cheap Volvo part at only £41 including VAT and 10% forum discount. I paid less than that for my first car in 1986. A Morris Marina for £40!