it's never worked since I've had the car and being in the UK I was never too bothered, but now that we have a summer(sic), it would be nice to have some cool air flowing thru. Green led on aircon button comes on, I found fuse 26 (30Amp was blown) but replacement makes no difference. Before I consider taking to an aircon specialist what checks can I make to find out if functionally operational or if I have a lack of coolant? 91' 730SEi 144k