I have had problems with my Citroen's Harrison V5 1135253 compressor. The original was leaking from the joint between the two halves. So last year I replace it with a second hand one- which had the same problem!!
This year I bought a brand new one for 350 €... which I have just put on, only to charge the system and it's not working

The clutch seems to engage and disengage immediately... the charge seems to have stayed in the system.
Any ideas why it might be engaging and disengaging immediately?
Thanks
Larry
ps the only odd thing was that it came with only one lead (+ve)- but i presumed the brown wire from the connector was +ve and attached the green and yellow one to earth. Apart from that I had no issues putting it on.